diff --git a/packages/ra-core/src/form/FormWithRedirect.tsx b/packages/ra-core/src/form/FormWithRedirect.tsx
index da85e6c62e6..2e5eb97615e 100644
--- a/packages/ra-core/src/form/FormWithRedirect.tsx
+++ b/packages/ra-core/src/form/FormWithRedirect.tsx
@@ -38,7 +38,9 @@ import { setAutomaticRefresh } from '../actions/uiActions';
  *
  * @param {Prop} props
  */
-const FormWithRedirect: FC<FormWithRedirectOwnProps & FormProps> = ({
+const FormWithRedirect: FC<
+    FormWithRedirectOwnProps & Omit<FormProps, 'onSubmit'>
+> = ({
     debug,
     decorators,
     defaultValue,
@@ -150,7 +152,7 @@ const FormWithRedirect: FC<FormWithRedirectOwnProps & FormProps> = ({
 export interface FormWithRedirectOwnProps {
     defaultValue?: any;
     record?: Record;
-    save: (
+    save?: (
         data: Partial<Record>,
         redirectTo: RedirectionSideEffect,
         options?: {
@@ -158,9 +160,9 @@ export interface FormWithRedirectOwnProps {
             onFailure?: (error: any) => void;
         }
     ) => void;
-    redirect: RedirectionSideEffect;
-    saving: boolean;
-    version: number;
+    redirect?: RedirectionSideEffect;
+    saving?: boolean;
+    version?: number;
     warnWhenUnsavedChanges?: boolean;
     sanitizeEmptyValues?: boolean;
 }
@@ -172,7 +174,12 @@ const defaultSubscription = {
     invalid: true,
 };
 
-const FormView = ({ render, warnWhenUnsavedChanges, ...props }) => {
+const FormView = ({
+    render,
+    warnWhenUnsavedChanges,
+    setRedirect,
+    ...props
+}) => {
     // if record changes (after a getOne success or a refresh), the form must be updated
     useInitializeFormWithRecord(props.record);
     useWarnWhenUnsavedChanges(warnWhenUnsavedChanges);
@@ -182,7 +189,7 @@ const FormView = ({ render, warnWhenUnsavedChanges, ...props }) => {
         dispatch(setAutomaticRefresh(props.pristine));
     }, [dispatch, props.pristine]);
 
-    const { redirect, setRedirect, handleSubmit } = props;
+    const { redirect, handleSubmit } = props;
 
     /**
      * We want to let developers define the redirection target from inside the form,
diff --git a/packages/ra-ui-materialui/src/form/FormInput.js b/packages/ra-ui-materialui/src/form/FormInput.tsx
similarity index 79%
rename from packages/ra-ui-materialui/src/form/FormInput.js
rename to packages/ra-ui-materialui/src/form/FormInput.tsx
index 3c48612bc40..647360e98db 100644
--- a/packages/ra-ui-materialui/src/form/FormInput.js
+++ b/packages/ra-ui-materialui/src/form/FormInput.tsx
@@ -1,9 +1,12 @@
 import * as React from 'react';
+import { FC, HtmlHTMLAttributes, ReactElement } from 'react';
 import PropTypes from 'prop-types';
 import classnames from 'classnames';
 import { makeStyles } from '@material-ui/core/styles';
+import { Record } from 'ra-core';
 
 import Labeled from '../input/Labeled';
+import { ClassesOverride } from '../types';
 
 const sanitizeRestProps = ({ basePath, record, ...rest }) => rest;
 
@@ -14,7 +17,7 @@ const useStyles = makeStyles(
     { name: 'RaFormInput' }
 );
 
-const FormInput = props => {
+const FormInput: FC<FormInputProps> = props => {
     const { input, classes: classesOverride, ...rest } = props;
     const classes = useStyles(props);
     return input ? (
@@ -59,11 +62,21 @@ const FormInput = props => {
 };
 
 FormInput.propTypes = {
-    className: PropTypes.string,
     classes: PropTypes.object,
-    input: PropTypes.object,
+    // @ts-ignore
+    input: PropTypes.node,
 };
 
+export interface FormInputProps extends HtmlHTMLAttributes<HTMLDivElement> {
+    basePath: string;
+    classes?: ClassesOverride<typeof useStyles>;
+    input: ReactElement;
+    margin?: 'none' | 'normal' | 'dense';
+    record: Record;
+    resource: string;
+    variant?: 'standard' | 'outlined' | 'filled';
+}
+
 // wat? TypeScript looses the displayName if we don't set it explicitly
 FormInput.displayName = 'FormInput';
 
diff --git a/packages/ra-ui-materialui/src/form/FormTab.spec.js b/packages/ra-ui-materialui/src/form/FormTab.spec.tsx
similarity index 98%
rename from packages/ra-ui-materialui/src/form/FormTab.spec.js
rename to packages/ra-ui-materialui/src/form/FormTab.spec.tsx
index 3925c2c369c..f03fbf98b0c 100644
--- a/packages/ra-ui-materialui/src/form/FormTab.spec.js
+++ b/packages/ra-ui-materialui/src/form/FormTab.spec.tsx
@@ -42,7 +42,7 @@ describe('<FormTab label="foo" />', () => {
     it('should render a TabbedForm with FormTabs having custom props without warnings', () => {
         const spy = jest.spyOn(console, 'error').mockImplementation(() => {});
 
-        const record = { name: 'foo' };
+        const record = { id: 'gazebo', name: 'foo' };
         const { container } = renderWithRedux(
             <TabbedForm>
                 <FormTab
diff --git a/packages/ra-ui-materialui/src/form/FormTab.js b/packages/ra-ui-materialui/src/form/FormTab.tsx
similarity index 79%
rename from packages/ra-ui-materialui/src/form/FormTab.js
rename to packages/ra-ui-materialui/src/form/FormTab.tsx
index 14aad6fe992..138c127d880 100644
--- a/packages/ra-ui-materialui/src/form/FormTab.js
+++ b/packages/ra-ui-materialui/src/form/FormTab.tsx
@@ -1,24 +1,16 @@
 import * as React from 'react';
+import { FC, ReactElement } from 'react';
 import PropTypes from 'prop-types';
 import { Link, useLocation } from 'react-router-dom';
 import MuiTab from '@material-ui/core/Tab';
 import classnames from 'classnames';
-import { useTranslate } from 'ra-core';
+import { useTranslate, Record } from 'ra-core';
 
 import FormInput from './FormInput';
 
-const sanitizeRestProps = ({
-    contentClassName,
-    label,
-    icon,
-    value,
-    translate,
-    ...rest
-}) => rest;
-
 const hiddenStyle = { display: 'none' };
 
-const FormTab = ({
+const FormTab: FC<FormTabProps> = ({
     basePath,
     className,
     contentClassName,
@@ -46,7 +38,7 @@ const FormTab = ({
             className={classnames('form-tab', className)}
             component={Link}
             to={{ ...location, pathname: value }}
-            {...sanitizeRestProps(rest)}
+            {...rest}
         />
     );
 
@@ -54,7 +46,7 @@ const FormTab = ({
         <span style={hidden ? hiddenStyle : null} className={contentClassName}>
             {React.Children.map(
                 children,
-                input =>
+                (input: ReactElement) =>
                     input && (
                         <FormInput
                             basePath={basePath}
@@ -83,12 +75,28 @@ FormTab.propTypes = {
     label: PropTypes.string.isRequired,
     margin: PropTypes.oneOf(['none', 'dense', 'normal']),
     path: PropTypes.string,
+    // @ts-ignore
     record: PropTypes.object,
     resource: PropTypes.string,
     value: PropTypes.string,
     variant: PropTypes.oneOf(['standard', 'outlined', 'filled']),
 };
 
+export interface FormTabProps {
+    basePath?: string;
+    className?: string;
+    contentClassName?: string;
+    hidden?: boolean;
+    icon?: ReactElement;
+    intent?: 'header' | 'content';
+    label: string;
+    margin?: 'none' | 'normal' | 'dense';
+    record?: Record;
+    resource?: string;
+    value?: string;
+    variant?: 'standard' | 'outlined' | 'filled';
+}
+
 FormTab.displayName = 'FormTab';
 
 export default FormTab;
diff --git a/packages/ra-ui-materialui/src/form/SimpleForm.spec.js b/packages/ra-ui-materialui/src/form/SimpleForm.spec.tsx
similarity index 88%
rename from packages/ra-ui-materialui/src/form/SimpleForm.spec.js
rename to packages/ra-ui-materialui/src/form/SimpleForm.spec.tsx
index 77e40c9c39b..5cd9f41b24f 100644
--- a/packages/ra-ui-materialui/src/form/SimpleForm.spec.js
+++ b/packages/ra-ui-materialui/src/form/SimpleForm.spec.tsx
@@ -35,28 +35,17 @@ describe('<SimpleForm />', () => {
     });
 
     it('should pass submitOnEnter to <Toolbar />', () => {
-        const handleSubmit = () => {};
-        const Toolbar = ({ submitOnEnter }) => (
+        const Toolbar = ({ submitOnEnter }: any): any => (
             <p>submitOnEnter: {submitOnEnter.toString()}</p>
         );
 
         const { queryByText, rerender } = renderWithRedux(
-            <SimpleForm
-                submitOnEnter={false}
-                handleSubmit={handleSubmit}
-                toolbar={<Toolbar />}
-            />
+            <SimpleForm submitOnEnter={false} toolbar={<Toolbar />} />
         );
 
         expect(queryByText('submitOnEnter: false')).not.toBeNull();
 
-        rerender(
-            <SimpleForm
-                submitOnEnter
-                handleSubmit={handleSubmit}
-                toolbar={<Toolbar />}
-            />
-        );
+        rerender(<SimpleForm submitOnEnter toolbar={<Toolbar />} />);
 
         expect(queryByText('submitOnEnter: true')).not.toBeNull();
     });
diff --git a/packages/ra-ui-materialui/src/form/SimpleForm.js b/packages/ra-ui-materialui/src/form/SimpleForm.tsx
similarity index 72%
rename from packages/ra-ui-materialui/src/form/SimpleForm.js
rename to packages/ra-ui-materialui/src/form/SimpleForm.tsx
index 46d351cf7e1..740d5e60565 100644
--- a/packages/ra-ui-materialui/src/form/SimpleForm.js
+++ b/packages/ra-ui-materialui/src/form/SimpleForm.tsx
@@ -1,8 +1,9 @@
 import * as React from 'react';
-import { Children } from 'react';
+import { Children, FC, ReactElement, HtmlHTMLAttributes } from 'react';
 import PropTypes from 'prop-types';
 import classnames from 'classnames';
-import { FormWithRedirect } from 'ra-core';
+import { FormWithRedirect, Record, RedirectionSideEffect } from 'ra-core';
+import { FormProps, FormRenderProps } from 'react-final-form';
 
 import FormInput from './FormInput';
 import Toolbar from './Toolbar';
@@ -39,11 +40,11 @@ import CardContentInner from '../layout/CardContentInner';
  * @prop {ReactElement} toolbar The element displayed at the bottom of the form, containing the SaveButton
  * @prop {string} variant Apply variant to all inputs. Possible values are 'standard', 'outlined', and 'filled' (default)
  * @prop {string} margin Apply variant to all inputs. Possible values are 'none', 'normal', and 'dense' (default)
- * @prop {boolean} sanitizeEmptyValues Wether or not deleted record attributes should be recreated with a `null` value (default: true)
+ * @prop {boolean} sanitizeEmptyValues Whether or not deleted record attributes should be recreated with a `null` value (default: true)
  *
  * @param {Prop} props
  */
-const SimpleForm = props => (
+const SimpleForm: FC<SimpleFormProps> = props => (
     <FormWithRedirect
         {...props}
         render={formProps => <SimpleFormView {...formProps} />}
@@ -52,8 +53,8 @@ const SimpleForm = props => (
 
 SimpleForm.propTypes = {
     children: PropTypes.node,
-    defaultValue: PropTypes.oneOfType([PropTypes.object, PropTypes.func]), // @deprecated
     initialValues: PropTypes.oneOfType([PropTypes.object, PropTypes.func]),
+    // @ts-ignore
     record: PropTypes.object,
     redirect: PropTypes.oneOfType([
         PropTypes.string,
@@ -70,7 +71,25 @@ SimpleForm.propTypes = {
     sanitizeEmptyValues: PropTypes.bool,
 };
 
-const SimpleFormView = ({
+export interface SimpleFormProps
+    extends Omit<FormProps, 'onSubmit'>,
+        Omit<HtmlHTMLAttributes<HTMLFormElement>, 'onSubmit' | 'children'> {
+    basePath?: string;
+    className?: string;
+    initialValues?: any;
+    margin?: 'none' | 'normal' | 'dense';
+    record?: Record;
+    redirect?: RedirectionSideEffect;
+    resource?: string;
+    sanitizeEmptyValues?: boolean;
+    submitOnEnter?: boolean;
+    toolbar?: ReactElement;
+    undoable?: boolean;
+    variant?: 'standard' | 'outlined' | 'filled';
+    warnWhenUnsavedChanges?: boolean;
+}
+
+const SimpleFormView: FC<SimpleFormViewProps> = ({
     basePath,
     children,
     className,
@@ -96,7 +115,7 @@ const SimpleFormView = ({
         <CardContentInner>
             {Children.map(
                 children,
-                input =>
+                (input: ReactElement) =>
                     input && (
                         <FormInput
                             basePath={basePath}
@@ -133,6 +152,7 @@ SimpleFormView.propTypes = {
     handleSubmit: PropTypes.func, // passed by react-final-form
     invalid: PropTypes.bool,
     pristine: PropTypes.bool,
+    // @ts-ignore
     record: PropTypes.object,
     resource: PropTypes.string,
     redirect: PropTypes.oneOfType([
@@ -148,62 +168,54 @@ SimpleFormView.propTypes = {
     validate: PropTypes.func,
 };
 
+export interface SimpleFormViewProps extends FormRenderProps {
+    basePath?: string;
+    className?: string;
+    margin?: 'none' | 'normal' | 'dense';
+    handleSubmitWithRedirect?: (redirectTo: RedirectionSideEffect) => void;
+    record?: Record;
+    redirect?: RedirectionSideEffect;
+    resource?: string;
+    save?: () => void;
+    saving?: boolean;
+    toolbar?: ReactElement;
+    undoable?: boolean;
+    variant?: 'standard' | 'outlined' | 'filled';
+    submitOnEnter?: boolean;
+    __versions?: any; // react-final-form internal prop, missing in their type
+}
+
 SimpleFormView.defaultProps = {
     submitOnEnter: true,
     toolbar: <Toolbar />,
 };
 
 const sanitizeRestProps = ({
-    anyTouched,
-    array,
-    asyncBlurFields,
-    asyncValidate,
-    asyncValidating,
-    autofill,
-    blur,
-    change,
-    clearAsyncError,
-    clearFields,
-    clearSubmit,
-    clearSubmitErrors,
-    destroy,
+    active,
     dirty,
     dirtyFields,
     dirtyFieldsSinceLastSubmit,
     dirtySinceLastSubmit,
-    dispatch,
+    error,
+    errors,
     form,
-    handleSubmit,
     hasSubmitErrors,
     hasValidationErrors,
-    initialize,
-    initialized,
     initialValues,
+    modified = null,
     modifiedSinceLastSubmit,
-    modifiedsincelastsubmit,
-    pristine,
-    pure,
-    redirect,
-    reset,
-    resetSection,
-    save,
-    setRedirect,
-    submit,
+    save = null,
     submitError,
     submitErrors,
-    submitAsSideEffect,
     submitFailed,
     submitSucceeded,
     submitting,
-    touch,
-    translate,
-    triggerSubmit,
-    undoable,
-    untouch,
+    touched = null,
     valid,
-    validate,
     validating,
-    __versions,
+    values,
+    visited = null,
+    __versions = null,
     ...props
 }) => props;
 
diff --git a/packages/ra-ui-materialui/src/form/SimpleFormIterator.spec.js b/packages/ra-ui-materialui/src/form/SimpleFormIterator.spec.tsx
similarity index 63%
rename from packages/ra-ui-materialui/src/form/SimpleFormIterator.spec.js
rename to packages/ra-ui-materialui/src/form/SimpleFormIterator.spec.tsx
index ab740a83d5c..e02305adaeb 100644
--- a/packages/ra-ui-materialui/src/form/SimpleFormIterator.spec.js
+++ b/packages/ra-ui-materialui/src/form/SimpleFormIterator.spec.tsx
@@ -1,12 +1,16 @@
 import { cleanup, fireEvent, wait, getByText } from '@testing-library/react';
 import * as React from 'react';
 import { renderWithRedux } from 'ra-core';
+import { ThemeProvider } from '@material-ui/core';
+import { createMuiTheme } from '@material-ui/core/styles';
 
 import SimpleFormIterator from './SimpleFormIterator';
 import TextInput from '../input/TextInput';
 import { ArrayInput } from '../input';
 import SimpleForm from './SimpleForm';
 
+const theme = createMuiTheme();
+
 describe('<SimpleFormIterator />', () => {
     // bypass confirm leave form with unsaved changes
     let confirmSpy;
@@ -48,13 +52,20 @@ describe('<SimpleFormIterator />', () => {
 
     it('should not display remove button if disableRemove is truthy', () => {
         const { queryAllByText } = renderWithRedux(
-            <SimpleForm record={{ emails: [{ email: '' }, { email: '' }] }}>
-                <ArrayInput source="emails">
-                    <SimpleFormIterator translate={x => x} disableRemove>
-                        <TextInput source="email" />
-                    </SimpleFormIterator>
-                </ArrayInput>
-            </SimpleForm>
+            <ThemeProvider theme={theme}>
+                <SimpleForm
+                    record={{
+                        id: 'whatever',
+                        emails: [{ email: '' }, { email: '' }],
+                    }}
+                >
+                    <ArrayInput source="emails">
+                        <SimpleFormIterator translate={x => x} disableRemove>
+                            <TextInput source="email" />
+                        </SimpleFormIterator>
+                    </ArrayInput>
+                </SimpleForm>
+            </ThemeProvider>
         );
 
         expect(queryAllByText('ra.action.remove').length).toBe(0);
@@ -100,7 +111,9 @@ describe('<SimpleFormIterator />', () => {
         );
 
         expect(
-            inputElements.map(inputElement => ({ email: inputElement.value }))
+            inputElements.map((inputElement: HTMLInputElement) => ({
+                email: inputElement.value,
+            }))
         ).toEqual([{ email: '' }, { email: '' }]);
 
         expect(queryAllByText('ra.action.remove').length).toBe(2);
@@ -115,7 +128,7 @@ describe('<SimpleFormIterator />', () => {
             <SimpleForm>
                 <ArrayInput source="emails">
                     <SimpleFormIterator translate={x => x}>
-                        <TextInput label="CustomLabel" />
+                        <TextInput source="email" label="CustomLabel" />
                     </SimpleFormIterator>
                 </ArrayInput>
             </SimpleForm>
@@ -132,9 +145,11 @@ describe('<SimpleFormIterator />', () => {
 
         const inputElements = queryAllByLabelText('CustomLabel');
 
-        expect(inputElements.map(inputElement => inputElement.value)).toEqual([
-            '',
-        ]);
+        expect(
+            inputElements.map(
+                (inputElement: HTMLInputElement) => inputElement.value
+            )
+        ).toEqual(['']);
 
         expect(queryAllByText('ra.action.remove').length).toBe(1);
     });
@@ -148,7 +163,11 @@ describe('<SimpleFormIterator />', () => {
             <SimpleForm>
                 <ArrayInput source="emails">
                     <SimpleFormIterator translate={x => x}>
-                        <TextInput label="CustomLabel" defaultValue={5} />
+                        <TextInput
+                            source="email"
+                            label="CustomLabel"
+                            defaultValue={5}
+                        />
                     </SimpleFormIterator>
                 </ArrayInput>
             </SimpleForm>
@@ -165,9 +184,11 @@ describe('<SimpleFormIterator />', () => {
 
         const inputElements = queryAllByLabelText('CustomLabel');
 
-        expect(inputElements.map(inputElement => inputElement.value)).toEqual([
-            '5',
-        ]);
+        expect(
+            inputElements.map(
+                (inputElement: HTMLInputElement) => inputElement.value
+            )
+        ).toEqual(['5']);
 
         expect(queryAllByText('ra.action.remove').length).toBe(1);
     });
@@ -176,13 +197,15 @@ describe('<SimpleFormIterator />', () => {
         const emails = [{ email: 'foo@bar.com' }, { email: 'bar@foo.com' }];
 
         const { queryAllByLabelText } = renderWithRedux(
-            <SimpleForm record={{ emails }}>
-                <ArrayInput source="emails">
-                    <SimpleFormIterator translate={x => x}>
-                        <TextInput source="email" />
-                    </SimpleFormIterator>
-                </ArrayInput>
-            </SimpleForm>
+            <ThemeProvider theme={theme}>
+                <SimpleForm record={{ id: 'whatever', emails }}>
+                    <ArrayInput source="emails">
+                        <SimpleFormIterator translate={x => x}>
+                            <TextInput source="email" />
+                        </SimpleFormIterator>
+                    </ArrayInput>
+                </SimpleForm>
+            </ThemeProvider>
         );
 
         const inputElements = queryAllByLabelText(
@@ -190,7 +213,9 @@ describe('<SimpleFormIterator />', () => {
         );
 
         expect(
-            inputElements.map(inputElement => ({ email: inputElement.value }))
+            inputElements.map((inputElement: HTMLInputElement) => ({
+                email: inputElement.value,
+            }))
         ).toEqual(emails);
 
         const removeFirstButton = getByText(
@@ -205,7 +230,7 @@ describe('<SimpleFormIterator />', () => {
             );
 
             expect(
-                inputElements.map(inputElement => ({
+                inputElements.map((inputElement: HTMLInputElement) => ({
                     email: inputElement.value,
                 }))
             ).toEqual([{ email: 'bar@foo.com' }]);
@@ -230,16 +255,20 @@ describe('<SimpleFormIterator />', () => {
 
     it('should not display the default remove button if a custom remove button is passed', () => {
         const { queryAllByText } = renderWithRedux(
-            <SimpleForm record={{ emails: [{ email: '' }] }}>
-                <ArrayInput source="emails">
-                    <SimpleFormIterator
-                        translate={x => x}
-                        removeButton={<button>Custom Remove Button</button>}
-                    >
-                        <TextInput source="email" />
-                    </SimpleFormIterator>
-                </ArrayInput>
-            </SimpleForm>
+            <ThemeProvider theme={theme}>
+                <SimpleForm
+                    record={{ id: 'whatever', emails: [{ email: '' }] }}
+                >
+                    <ArrayInput source="emails">
+                        <SimpleFormIterator
+                            translate={x => x}
+                            removeButton={<button>Custom Remove Button</button>}
+                        >
+                            <TextInput source="email" />
+                        </SimpleFormIterator>
+                    </ArrayInput>
+                </SimpleForm>
+            </ThemeProvider>
         );
 
         expect(queryAllByText('ra.action.remove').length).toBe(0);
@@ -264,16 +293,20 @@ describe('<SimpleFormIterator />', () => {
 
     it('should display the custom remove button', () => {
         const { getByText } = renderWithRedux(
-            <SimpleForm record={{ emails: [{ email: '' }] }}>
-                <ArrayInput source="emails">
-                    <SimpleFormIterator
-                        translate={x => x}
-                        removeButton={<button>Custom Remove Button</button>}
-                    >
-                        <TextInput source="email" />
-                    </SimpleFormIterator>
-                </ArrayInput>
-            </SimpleForm>
+            <ThemeProvider theme={theme}>
+                <SimpleForm
+                    record={{ id: 'whatever', emails: [{ email: '' }] }}
+                >
+                    <ArrayInput source="emails">
+                        <SimpleFormIterator
+                            translate={x => x}
+                            removeButton={<button>Custom Remove Button</button>}
+                        >
+                            <TextInput source="email" />
+                        </SimpleFormIterator>
+                    </ArrayInput>
+                </SimpleForm>
+            </ThemeProvider>
         );
 
         expect(getByText('Custom Remove Button')).toBeDefined();
@@ -282,18 +315,22 @@ describe('<SimpleFormIterator />', () => {
     it('should call the onClick method when the custom add button is clicked', async () => {
         const onClick = jest.fn();
         const { getByText } = renderWithRedux(
-            <SimpleForm>
-                <ArrayInput source="emails">
-                    <SimpleFormIterator
-                        translate={x => x}
-                        addButton={
-                            <button onClick={onClick}>Custom Add Button</button>
-                        }
-                    >
-                        <TextInput source="email" />
-                    </SimpleFormIterator>
-                </ArrayInput>
-            </SimpleForm>
+            <ThemeProvider theme={theme}>
+                <SimpleForm>
+                    <ArrayInput source="emails">
+                        <SimpleFormIterator
+                            translate={x => x}
+                            addButton={
+                                <button onClick={onClick}>
+                                    Custom Add Button
+                                </button>
+                            }
+                        >
+                            <TextInput source="email" />
+                        </SimpleFormIterator>
+                    </ArrayInput>
+                </SimpleForm>
+            </ThemeProvider>
         );
         fireEvent.click(getByText('Custom Add Button'));
         expect(onClick).toHaveBeenCalled();
@@ -302,20 +339,24 @@ describe('<SimpleFormIterator />', () => {
     it('should call the onClick method when the custom remove button is clicked', async () => {
         const onClick = jest.fn();
         const { getByText } = renderWithRedux(
-            <SimpleForm record={{ emails: [{ email: '' }] }}>
-                <ArrayInput source="emails">
-                    <SimpleFormIterator
-                        translate={x => x}
-                        removeButton={
-                            <button onClick={onClick}>
-                                Custom Remove Button
-                            </button>
-                        }
-                    >
-                        <TextInput source="email" />
-                    </SimpleFormIterator>
-                </ArrayInput>
-            </SimpleForm>
+            <ThemeProvider theme={theme}>
+                <SimpleForm
+                    record={{ id: 'whatever', emails: [{ email: '' }] }}
+                >
+                    <ArrayInput source="emails">
+                        <SimpleFormIterator
+                            translate={x => x}
+                            removeButton={
+                                <button onClick={onClick}>
+                                    Custom Remove Button
+                                </button>
+                            }
+                        >
+                            <TextInput source="email" />
+                        </SimpleFormIterator>
+                    </ArrayInput>
+                </SimpleForm>
+            </ThemeProvider>
         );
         fireEvent.click(getByText('Custom Remove Button'));
         expect(onClick).toHaveBeenCalled();
diff --git a/packages/ra-ui-materialui/src/form/SimpleFormIterator.js b/packages/ra-ui-materialui/src/form/SimpleFormIterator.tsx
similarity index 75%
rename from packages/ra-ui-materialui/src/form/SimpleFormIterator.js
rename to packages/ra-ui-materialui/src/form/SimpleFormIterator.tsx
index 6b7c430a33c..c3d87bc3ab4 100644
--- a/packages/ra-ui-materialui/src/form/SimpleFormIterator.js
+++ b/packages/ra-ui-materialui/src/form/SimpleFormIterator.tsx
@@ -1,5 +1,12 @@
 import * as React from 'react';
-import { Children, cloneElement, isValidElement, useRef } from 'react';
+import {
+    Children,
+    cloneElement,
+    isValidElement,
+    useRef,
+    ReactElement,
+    FC,
+} from 'react';
 import PropTypes from 'prop-types';
 import { CSSTransition, TransitionGroup } from 'react-transition-group';
 import get from 'lodash/get';
@@ -12,7 +19,7 @@ import AddIcon from '@material-ui/icons/AddCircleOutline';
 import { useTranslate, ValidationError } from 'ra-core';
 import classNames from 'classnames';
 
-import FormInput from '../form/FormInput';
+import FormInput from './FormInput';
 
 const useStyles = makeStyles(
     theme => ({
@@ -85,7 +92,7 @@ const DefaultRemoveButton = props => {
     );
 };
 
-const SimpleFormIterator = props => {
+const SimpleFormIterator: FC<any> = props => {
     const {
         addButton = <DefaultAddButton />,
         removeButton = <DefaultRemoveButton />,
@@ -187,41 +194,47 @@ const SimpleFormIterator = props => {
                                 {index + 1}
                             </Typography>
                             <section className={classes.form}>
-                                {Children.map(children, (input, index2) =>
-                                    isValidElement(input) ? (
-                                        <FormInput
-                                            basePath={
-                                                input.props.basePath || basePath
-                                            }
-                                            input={cloneElement(input, {
-                                                source: input.props.source
-                                                    ? `${member}.${
-                                                          input.props.source
-                                                      }`
-                                                    : member,
-                                                index: input.props.source
-                                                    ? undefined
-                                                    : index2,
-                                                label:
-                                                    typeof input.props.label ===
-                                                    'undefined'
-                                                        ? input.props.source
-                                                            ? `resources.${resource}.fields.${
-                                                                  input.props
-                                                                      .source
-                                                              }`
-                                                            : undefined
-                                                        : input.props.label,
-                                            })}
-                                            record={
-                                                (records && records[index]) ||
-                                                {}
-                                            }
-                                            resource={resource}
-                                            variant={variant}
-                                            margin={margin}
-                                        />
-                                    ) : null
+                                {Children.map(
+                                    children,
+                                    (input: ReactElement, index2) =>
+                                        isValidElement<any>(input) ? (
+                                            <FormInput
+                                                basePath={
+                                                    input.props.basePath ||
+                                                    basePath
+                                                }
+                                                input={cloneElement(input, {
+                                                    source: input.props.source
+                                                        ? `${member}.${
+                                                              input.props.source
+                                                          }`
+                                                        : member,
+                                                    index: input.props.source
+                                                        ? undefined
+                                                        : index2,
+                                                    label:
+                                                        typeof input.props
+                                                            .label ===
+                                                        'undefined'
+                                                            ? input.props.source
+                                                                ? `resources.${resource}.fields.${
+                                                                      input
+                                                                          .props
+                                                                          .source
+                                                                  }`
+                                                                : undefined
+                                                            : input.props.label,
+                                                })}
+                                                record={
+                                                    (records &&
+                                                        records[index]) ||
+                                                    {}
+                                                }
+                                                resource={resource}
+                                                variant={variant}
+                                                margin={margin}
+                                            />
+                                        ) : null
                                 )}
                             </section>
                             {!disableRemoveField(
diff --git a/packages/ra-ui-materialui/src/form/TabbedForm.spec.js b/packages/ra-ui-materialui/src/form/TabbedForm.spec.tsx
similarity index 98%
rename from packages/ra-ui-materialui/src/form/TabbedForm.spec.js
rename to packages/ra-ui-materialui/src/form/TabbedForm.spec.tsx
index 866298afdc8..177b0796542 100644
--- a/packages/ra-ui-materialui/src/form/TabbedForm.spec.js
+++ b/packages/ra-ui-materialui/src/form/TabbedForm.spec.tsx
@@ -25,7 +25,7 @@ describe('<TabbedForm />', () => {
     });
 
     it('should pass submitOnEnter to <Toolbar />', () => {
-        const Toolbar = ({ submitOnEnter }) => (
+        const Toolbar = ({ submitOnEnter }: any) => (
             <p>submitOnEnter: {submitOnEnter.toString()}</p>
         );
 
diff --git a/packages/ra-ui-materialui/src/form/TabbedForm.js b/packages/ra-ui-materialui/src/form/TabbedForm.tsx
similarity index 97%
rename from packages/ra-ui-materialui/src/form/TabbedForm.js
rename to packages/ra-ui-materialui/src/form/TabbedForm.tsx
index 35a8c36566d..6ade98012d1 100644
--- a/packages/ra-ui-materialui/src/form/TabbedForm.js
+++ b/packages/ra-ui-materialui/src/form/TabbedForm.tsx
@@ -1,5 +1,5 @@
 import * as React from 'react';
-import { Children, isValidElement } from 'react';
+import { Children, isValidElement, FC, ReactElement } from 'react';
 import PropTypes from 'prop-types';
 import classnames from 'classnames';
 import { Route, useRouteMatch, useLocation } from 'react-router-dom';
@@ -78,7 +78,7 @@ import TabbedFormTabs, { getTabFullPath } from './TabbedFormTabs';
  *
  * @param {Prop} props
  */
-const TabbedForm = props => (
+const TabbedForm: FC<any> = props => (
     <FormWithRedirect
         {...props}
         render={formProps => <TabbedFormView {...formProps} />}
@@ -169,7 +169,7 @@ export const TabbedFormView = props => {
                 See https://github.com/marmelab/react-admin/issues/1866 */}
                 {Children.map(
                     children,
-                    (tab, index) =>
+                    (tab: ReactElement, index) =>
                         tab && (
                             <Route
                                 exact
@@ -178,7 +178,7 @@ export const TabbedFormView = props => {
                                 )}
                             >
                                 {routeProps =>
-                                    isValidElement(tab)
+                                    isValidElement<any>(tab)
                                         ? React.cloneElement(tab, {
                                               intent: 'content',
                                               resource,
@@ -308,7 +308,7 @@ const sanitizeRestProps = ({
 }) => props;
 
 export const findTabsWithErrors = (children, errors) => {
-    return Children.toArray(children).reduce((acc, child) => {
+    return Children.toArray(children).reduce((acc: any[], child) => {
         if (!isValidElement(child)) {
             return acc;
         }
diff --git a/packages/ra-ui-materialui/src/form/TabbedFormTabs.spec.js b/packages/ra-ui-materialui/src/form/TabbedFormTabs.spec.tsx
similarity index 100%
rename from packages/ra-ui-materialui/src/form/TabbedFormTabs.spec.js
rename to packages/ra-ui-materialui/src/form/TabbedFormTabs.spec.tsx
index c27cc933d94..0f397ff1850 100644
--- a/packages/ra-ui-materialui/src/form/TabbedFormTabs.spec.js
+++ b/packages/ra-ui-materialui/src/form/TabbedFormTabs.spec.tsx
@@ -1,9 +1,9 @@
 import * as React from 'react';
 import { render, cleanup } from '@testing-library/react';
+import { MemoryRouter } from 'react-router-dom';
 
 import TabbedFormTabs from './TabbedFormTabs';
 import FormTab from './FormTab';
-import { MemoryRouter } from 'react-router-dom';
 
 describe('<TabbedFormTabs />', () => {
     afterEach(cleanup);
diff --git a/packages/ra-ui-materialui/src/form/TabbedFormTabs.js b/packages/ra-ui-materialui/src/form/TabbedFormTabs.tsx
similarity index 78%
rename from packages/ra-ui-materialui/src/form/TabbedFormTabs.js
rename to packages/ra-ui-materialui/src/form/TabbedFormTabs.tsx
index 9e670b1255d..297227f93f6 100644
--- a/packages/ra-ui-materialui/src/form/TabbedFormTabs.js
+++ b/packages/ra-ui-materialui/src/form/TabbedFormTabs.tsx
@@ -1,15 +1,16 @@
 import * as React from 'react';
-import { Children, cloneElement, isValidElement } from 'react';
+import {
+    Children,
+    cloneElement,
+    isValidElement,
+    FC,
+    ReactElement,
+} from 'react';
 import PropTypes from 'prop-types';
-import Tabs from '@material-ui/core/Tabs';
+import Tabs, { TabsProps } from '@material-ui/core/Tabs';
 import { useLocation } from 'react-router-dom';
 
-export const getTabFullPath = (tab, index, baseUrl) =>
-    `${baseUrl}${
-        tab.props.path ? `/${tab.props.path}` : index > 0 ? `/${index}` : ''
-    }`;
-
-const TabbedFormTabs = ({
+const TabbedFormTabs: FC<TabbedFormTabsProps> = ({
     children,
     classes,
     url,
@@ -36,8 +37,8 @@ const TabbedFormTabs = ({
 
     return (
         <Tabs value={tabValue} indicatorColor="primary" {...rest}>
-            {Children.map(children, (tab, index) => {
-                if (!isValidElement(tab)) return null;
+            {Children.map(children, (tab: ReactElement, index) => {
+                if (!isValidElement<any>(tab)) return null;
 
                 // Builds the full tab tab which is the concatenation of the last matched route in the
                 // TabbedShowLayout hierarchy (ex: '/posts/create', '/posts/12', , '/posts/12/show')
@@ -66,4 +67,19 @@ TabbedFormTabs.propTypes = {
     tabsWithErrors: PropTypes.arrayOf(PropTypes.string),
 };
 
+export const getTabFullPath = (
+    tab: ReactElement,
+    index: number,
+    baseUrl: string
+): string =>
+    `${baseUrl}${
+        tab.props.path ? `/${tab.props.path}` : index > 0 ? `/${index}` : ''
+    }`;
+
+export interface TabbedFormTabsProps extends Omit<TabsProps, 'value'> {
+    classes?: any;
+    url?: string;
+    tabsWithErrors?: string[];
+}
+
 export default TabbedFormTabs;
diff --git a/packages/ra-ui-materialui/src/form/Toolbar.js b/packages/ra-ui-materialui/src/form/Toolbar.tsx
similarity index 96%
rename from packages/ra-ui-materialui/src/form/Toolbar.js
rename to packages/ra-ui-materialui/src/form/Toolbar.tsx
index ae1c25cf228..483be205427 100644
--- a/packages/ra-ui-materialui/src/form/Toolbar.js
+++ b/packages/ra-ui-materialui/src/form/Toolbar.tsx
@@ -1,5 +1,5 @@
 import * as React from 'react';
-import { Children, Fragment, isValidElement } from 'react';
+import { Children, Fragment, isValidElement, ReactElement, FC } from 'react';
 import PropTypes from 'prop-types';
 import MuiToolbar from '@material-ui/core/Toolbar';
 import withWidth from '@material-ui/core/withWidth';
@@ -84,7 +84,7 @@ const valueOrDefault = (value, defaultValue) =>
  * @prop {string} width Apply the mobile or the desktop classes depending on the width. Pass "xs" to display the mobile version.
  *
  */
-const Toolbar = props => {
+const Toolbar: FC<any> = props => {
     const {
         alwaysEnableSaveButton,
         basePath,
@@ -134,7 +134,6 @@ const Toolbar = props => {
                             invalid={invalid}
                             redirect={redirect}
                             saving={saving}
-                            pristine={pristine}
                             submitOnEnter={submitOnEnter}
                         />
                         {record && typeof record.id !== 'undefined' && (
@@ -147,8 +146,8 @@ const Toolbar = props => {
                         )}
                     </div>
                 ) : (
-                    Children.map(children, button =>
-                        button && isValidElement(button)
+                    Children.map(children, (button: ReactElement) =>
+                        button && isValidElement<any>(button)
                             ? React.cloneElement(button, {
                                   basePath,
                                   handleSubmit: valueOrDefault(
diff --git a/packages/ra-ui-materialui/src/form/getFormInitialValues.js b/packages/ra-ui-materialui/src/form/getFormInitialValues.ts
similarity index 67%
rename from packages/ra-ui-materialui/src/form/getFormInitialValues.js
rename to packages/ra-ui-materialui/src/form/getFormInitialValues.ts
index 86be4438f2b..f2c81909979 100644
--- a/packages/ra-ui-materialui/src/form/getFormInitialValues.js
+++ b/packages/ra-ui-materialui/src/form/getFormInitialValues.ts
@@ -1,8 +1,10 @@
+import { Record } from 'ra-core';
+
 export default function getFormInitialValues(
-    initialValues,
-    defaultValue,
-    record
-) {
+    initialValues: any,
+    defaultValue: DefaultValue,
+    record: Record
+): any {
     let finalInitialValues = {
         ...initialValues,
         ...record,
@@ -28,3 +30,9 @@ export default function getFormInitialValues(
 
     return finalInitialValues;
 }
+
+interface DefaultValueObject {
+    [key: string]: any;
+}
+type DefaultValueFunction = (record: Record) => DefaultValueObject;
+type DefaultValue = DefaultValueObject | DefaultValueFunction;
diff --git a/packages/ra-ui-materialui/src/form/index.js b/packages/ra-ui-materialui/src/form/index.tsx
similarity index 100%
rename from packages/ra-ui-materialui/src/form/index.js
rename to packages/ra-ui-materialui/src/form/index.tsx
diff --git a/packages/ra-ui-materialui/src/input/ArrayInput.tsx b/packages/ra-ui-materialui/src/input/ArrayInput.tsx
index 441c79f7615..4da37544e74 100644
--- a/packages/ra-ui-materialui/src/input/ArrayInput.tsx
+++ b/packages/ra-ui-materialui/src/input/ArrayInput.tsx
@@ -1,7 +1,7 @@
 import * as React from 'react';
-import { cloneElement, Children } from 'react';
+import { cloneElement, Children, FC, ReactElement } from 'react';
 import PropTypes from 'prop-types';
-import { isRequired, FieldTitle, composeValidators } from 'ra-core';
+import { isRequired, FieldTitle, composeValidators, InputProps } from 'ra-core';
 import { useFieldArray } from 'react-final-form-arrays';
 import { InputLabel, FormControl } from '@material-ui/core';
 
@@ -48,7 +48,7 @@ import sanitizeRestProps from './sanitizeRestProps';
  *
  * @see https://github.com/final-form/react-final-form-arrays
  */
-const ArrayInput = ({
+const ArrayInput: FC<ArrayInputProps> = ({
     className,
     defaultValue,
     label,
@@ -99,6 +99,7 @@ const ArrayInput = ({
 };
 
 ArrayInput.propTypes = {
+    // @ts-ignore
     children: PropTypes.node,
     className: PropTypes.string,
     defaultValue: PropTypes.any,
@@ -118,4 +119,8 @@ ArrayInput.defaultProps = {
     options: {},
     fullWidth: true,
 };
+
+export interface ArrayInputProps extends InputProps {
+    children: ReactElement;
+}
 export default ArrayInput;