diff --git a/tester/tester.go b/tester/tester.go
index f5e944b0..471ee4af 100644
--- a/tester/tester.go
+++ b/tester/tester.go
@@ -541,6 +541,33 @@ func (wt *workflowTester[TResult]) sendEvent(wfi *core.WorkflowInstance, event *
 	w.pendingEvents = append(w.pendingEvents, event)
 }
 
+// CancelWorkflow cancels the workflow under test.
+func (wt *workflowTester[TResult]) CancelWorkflow() {
+	_ = wt.CancelWorkflowInstance(wt.wfi)
+}
+
+// CancelWorkflowInstance cancels the given workflow instance.
+func (wt *workflowTester[TResult]) CancelWorkflowInstance(wfi *core.WorkflowInstance) error {
+	if wt.getWorkflow(wfi) == nil {
+		return backend.ErrInstanceNotFound
+	}
+
+	wt.callbacks <- func() *history.WorkflowEvent {
+		e := history.NewPendingEvent(
+			wt.clock.Now(),
+			history.EventType_WorkflowExecutionCanceled,
+			&history.ExecutionCanceledAttributes{},
+		)
+
+		return &history.WorkflowEvent{
+			WorkflowInstance: wfi,
+			HistoryEvent:     e,
+		}
+	}
+
+	return nil
+}
+
 // SignalWorkflow sends a signal to the workflow under test.
 func (wt *workflowTester[TResult]) SignalWorkflow(name string, value any) {
 	wt.SignalWorkflowInstance(wt.wfi, name, value)
diff --git a/tester/tester_subworkflow_test.go b/tester/tester_subworkflow_test.go
index 489ab685..72168c03 100644
--- a/tester/tester_subworkflow_test.go
+++ b/tester/tester_subworkflow_test.go
@@ -3,6 +3,7 @@ package tester
 import (
 	"context"
 	"errors"
+	"fmt"
 	"testing"
 	"time"
 
@@ -109,6 +110,47 @@ func Test_SubWorkflow_Mocked_Failure(t *testing.T) {
 	tester.AssertExpectations(t)
 }
 
+func Test_SubWorkflow_Cancel(t *testing.T) {
+	subWorkflow := func(ctx workflow.Context) error {
+		_, _ = ctx.Done().Receive(ctx)
+		return ctx.Err()
+	}
+
+	workflowWithSub := func(ctx workflow.Context) error {
+		_, err := workflow.CreateSubWorkflowInstance[any](
+			ctx,
+			workflow.DefaultSubWorkflowOptions,
+			subWorkflow,
+		).Get(ctx)
+		if err != nil {
+			return fmt.Errorf("subworkflow: %w", err)
+		}
+
+		return nil
+	}
+
+	tester := NewWorkflowTester[string](workflowWithSub)
+	tester.Registry().RegisterWorkflow(subWorkflow)
+
+	var subWorkflowInstance *core.WorkflowInstance
+
+	tester.ListenSubWorkflow(func(instance *core.WorkflowInstance, _ string) {
+		subWorkflowInstance = instance
+	})
+
+	tester.ScheduleCallback(time.Millisecond, func() {
+		require.NoError(t, tester.CancelWorkflowInstance(subWorkflowInstance))
+	})
+
+	tester.Execute(context.Background())
+
+	require.True(t, tester.WorkflowFinished())
+
+	_, err := tester.WorkflowResult()
+	require.EqualError(t, err, "subworkflow: context canceled")
+	tester.AssertExpectations(t)
+}
+
 func Test_SubWorkflow_Signals(t *testing.T) {
 	subWorkflow := func(ctx workflow.Context, input string) (string, error) {
 		c := workflow.NewSignalChannel[string](ctx, "subworkflow-signal")
diff --git a/tester/tester_test.go b/tester/tester_test.go
index 3aa745ab..f67ab0fd 100644
--- a/tester/tester_test.go
+++ b/tester/tester_test.go
@@ -161,6 +161,22 @@ func activityLongRunning(ctx context.Context) (int, error) {
 	return 42, nil
 }
 
+func Test_CancelWorkflow(t *testing.T) {
+	tester := NewWorkflowTester[any](func(ctx workflow.Context) error {
+		_, _ = ctx.Done().Receive(ctx)
+		return ctx.Err()
+	})
+	tester.ScheduleCallback(time.Duration(time.Second), func() {
+		tester.CancelWorkflow()
+	})
+
+	tester.Execute(context.Background())
+
+	require.True(t, tester.WorkflowFinished())
+	_, err := tester.WorkflowResult()
+	require.EqualError(t, err, "context canceled")
+}
+
 func Test_Signals(t *testing.T) {
 	tester := NewWorkflowTester[string](workflowSignal)
 	tester.ScheduleCallback(time.Duration(5*time.Second), func() {