diff --git a/Gopkg.lock b/Gopkg.lock
index 1b766e9ff54..4b6d6ba5441 100644
--- a/Gopkg.lock
+++ b/Gopkg.lock
@@ -274,6 +274,12 @@
   packages = ["."]
   revision = "55d61fa8aa702f59229e6cff85793c22e580eaf5"
 
+[[projects]]
+  name = "github.com/sanity-io/litter"
+  packages = ["."]
+  revision = "ae543b7ba8fd6af63e4976198f146e1348ae53c1"
+  version = "v1.1.0"
+
 [[projects]]
   branch = "master"
   name = "github.com/shurcooL/sanitized_anchor_name"
@@ -417,6 +423,6 @@
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "4657586103d844434bda6db23d03f30e2ae0db16dc48746b9559ce742902535a"
+  inputs-digest = "13ab39f8bfafadc12c05726e565ee3f3d94bf7d6c0e8adf04056de0691bf2dd6"
   solver-name = "gps-cdcl"
   solver-version = 1
diff --git a/Gopkg.toml b/Gopkg.toml
index 4e0cd5c6b07..fc1af824bc4 100644
--- a/Gopkg.toml
+++ b/Gopkg.toml
@@ -141,3 +141,7 @@
   name = "github.com/muesli/smartcrop"
   branch = "master"
 
+
+[[constraint]]
+  name = "github.com/sanity-io/litter"
+  version = "1.1.0"
diff --git a/commands/hugo.go b/commands/hugo.go
index a13aa91b540..4424590c9da 100644
--- a/commands/hugo.go
+++ b/commands/hugo.go
@@ -306,7 +306,14 @@ func InitializeConfig(running bool, doWithCommandeer func(c *commandeer) error,
 	// Init file systems. This may be changed at a later point.
 	osFs := hugofs.Os
 
-	config, err := hugolib.LoadConfig(hugolib.ConfigSourceDescriptor{Fs: osFs, Src: source, Name: cfgFile})
+	var dir string
+	if source != "" {
+		dir, _ = filepath.Abs(source)
+	} else {
+		dir, _ = os.Getwd()
+	}
+
+	config, err := hugolib.LoadConfig(hugolib.ConfigSourceDescriptor{Fs: osFs, Src: source, WorkingDir: dir, Name: cfgFile})
 	if err != nil {
 		return nil, err
 	}
@@ -358,12 +365,6 @@ func InitializeConfig(running bool, doWithCommandeer func(c *commandeer) error,
 		config.Set("publishDir", destination)
 	}
 
-	var dir string
-	if source != "" {
-		dir, _ = filepath.Abs(source)
-	} else {
-		dir, _ = os.Getwd()
-	}
 	config.Set("workingDir", dir)
 
 	if contentDir != "" {
diff --git a/helpers/path.go b/helpers/path.go
index 44d53d018df..0a854435770 100644
--- a/helpers/path.go
+++ b/helpers/path.go
@@ -154,11 +154,16 @@ func ReplaceExtension(path string, newExt string) string {
 // AbsPathify creates an absolute path if given a relative path. If already
 // absolute, the path is just cleaned.
 func (p *PathSpec) AbsPathify(inPath string) string {
+	return AbsPathify(p.workingDir, inPath)
+}
+
+// AbsPathify creates an absolute path if given a working dir and arelative path.
+// If already absolute, the path is just cleaned.
+func AbsPathify(workingDir, inPath string) string {
 	if filepath.IsAbs(inPath) {
 		return filepath.Clean(inPath)
 	}
-
-	return filepath.Join(p.workingDir, inPath)
+	return filepath.Join(workingDir, inPath)
 }
 
 // GetLayoutDirPath returns the absolute path to the layout file dir
diff --git a/hugolib/config.go b/hugolib/config.go
index e47e65435b1..9a22d70c8c1 100644
--- a/hugolib/config.go
+++ b/hugolib/config.go
@@ -16,6 +16,7 @@ package hugolib
 import (
 	"errors"
 	"fmt"
+	"path/filepath"
 
 	"io"
 	"strings"
@@ -28,9 +29,10 @@ import (
 
 // ConfigSourceDescriptor describes where to find the config (e.g. config.toml etc.).
 type ConfigSourceDescriptor struct {
-	Fs   afero.Fs
-	Src  string
-	Name string
+	Fs         afero.Fs
+	Src        string
+	WorkingDir string
+	Name       string
 }
 
 func (d ConfigSourceDescriptor) configFilenames() []string {
@@ -85,7 +87,16 @@ func LoadConfig(d ConfigSourceDescriptor) (*viper.Viper, error) {
 		return v, err
 	}
 
+	if err := loadThemeConfig(d, v); err != nil {
+		return v, err
+	}
+
+	if err := loadLanguageSettings(v, nil); err != nil {
+		return v, err
+	}
+
 	return v, nil
+
 }
 
 func loadLanguageSettings(cfg config.Provider, oldLangs helpers.Languages) error {
@@ -201,6 +212,127 @@ func loadLanguageSettings(cfg config.Provider, oldLangs helpers.Languages) error
 	return nil
 }
 
+func loadThemeConfig(d ConfigSourceDescriptor, v1 *viper.Viper) error {
+
+	theme := v1.GetString("theme")
+	if theme == "" {
+		return nil
+	}
+
+	themesDir := helpers.AbsPathify(d.WorkingDir, v1.GetString("themesDir"))
+	configDir := filepath.Join(themesDir, theme)
+
+	var (
+		configPath string
+		exists     bool
+		err        error
+	)
+
+	// Viper supports more, but this is the sub-set supported by Hugo.
+	for _, configFormats := range []string{"toml", "yaml", "yml", "json"} {
+		configPath = filepath.Join(configDir, "config."+configFormats)
+		exists, err = helpers.Exists(configPath, d.Fs)
+		if err != nil {
+			return err
+		}
+		if exists {
+			break
+		}
+	}
+
+	if !exists {
+		// No theme config set.
+		return nil
+	}
+
+	v2 := viper.New()
+	v2.SetFs(d.Fs)
+	v2.AutomaticEnv()
+	v2.SetEnvPrefix("hugo")
+	v2.SetConfigFile(configPath)
+
+	err = v2.ReadInConfig()
+	if err != nil {
+		return err
+	}
+
+	const (
+		paramsKey    = "params"
+		languagesKey = "languages"
+		menuKey      = "menu"
+	)
+
+	for _, key := range []string{"params", "outputformats", "mediatypes"} {
+		mergeStringMapKeepLeft(key, v1, v2)
+	}
+
+	themeLower := strings.ToLower(theme)
+	themeParamsNamespace := paramsKey + "." + themeLower
+	// Set namespaced params
+
+	if v2.IsSet(paramsKey) && !v1.IsSet(themeParamsNamespace) {
+		// Set it in the default store to make sure it gets in the same or
+		// behind the others.
+		v1.SetDefault(themeParamsNamespace, v2.Get(paramsKey))
+	}
+
+	// Only add params, we do not add language definitions.
+	if v1.IsSet("languages") && v2.IsSet("languages") {
+		v1Langs := v1.GetStringMap(languagesKey)
+		for k, _ := range v1Langs {
+			mergeStringMapKeepLeft(languagesKey+"."+k+"."+paramsKey, v1, v2)
+		}
+		v2Langs := v2.GetStringMap(languagesKey)
+		for k, _ := range v2Langs {
+			if k == "" {
+				continue
+			}
+			langParamsKey := languagesKey + "." + k + "." + paramsKey
+			langParamsThemeNamespace := langParamsKey + "." + themeLower
+			// Set namespaced params
+			if v2.IsSet(langParamsKey) && !v1.IsSet(langParamsThemeNamespace) {
+				v1.SetDefault(langParamsThemeNamespace, v2.Get(langParamsKey))
+			}
+		}
+	}
+
+	// Add menu definitions from theme not found in project
+	if v2.IsSet("menu") {
+		v2menus := v2.GetStringMap(menuKey)
+		for k, v := range v2menus {
+			if !v1.IsSet(menuKey + "." + k) {
+				v1.SetDefault(menuKey+"."+k, v)
+			}
+		}
+	}
+
+	return nil
+
+}
+
+func mergeStringMapKeepLeft(key string, v1, v2 *viper.Viper) {
+
+	if !v1.IsSet(key) {
+		if v2.IsSet(key) {
+			v1.SetDefault(key, v2.Get(key))
+		}
+		return
+	}
+
+	if !v2.IsSet(key) {
+		return
+	}
+
+	m1 := v1.GetStringMap(key)
+	m2 := v2.GetStringMap(key)
+
+	for k, v := range m2 {
+		if _, found := m1[k]; !found {
+			m1[k] = v
+		}
+	}
+}
+
 func loadDefaultSettingsFor(v *viper.Viper) error {
 
 	c, err := helpers.NewContentSpec(v)
@@ -281,5 +413,5 @@ lastmod = ["lastmod" ,":fileModTime", ":default"]
 
 	}
 
-	return loadLanguageSettings(v, nil)
+	return nil
 }
diff --git a/hugolib/config_test.go b/hugolib/config_test.go
index ec543d93dc6..21bbc9350e0 100644
--- a/hugolib/config_test.go
+++ b/hugolib/config_test.go
@@ -17,13 +17,15 @@ import (
 	"testing"
 
 	"github.com/spf13/afero"
-	"github.com/stretchr/testify/assert"
+	"github.com/spf13/viper"
 	"github.com/stretchr/testify/require"
 )
 
 func TestLoadConfig(t *testing.T) {
 	t.Parallel()
 
+	assert := require.New(t)
+
 	// Add a random config variable for testing.
 	// side = page in Norwegian.
 	configContent := `
@@ -37,13 +39,16 @@ func TestLoadConfig(t *testing.T) {
 	cfg, err := LoadConfig(ConfigSourceDescriptor{Fs: mm, Name: "hugo.toml"})
 	require.NoError(t, err)
 
-	assert.Equal(t, "side", cfg.GetString("paginatePath"))
+	assert.Equal("side", cfg.GetString("paginatePath"))
 	// default
-	assert.Equal(t, "layouts", cfg.GetString("layoutDir"))
+	assert.Equal("layouts", cfg.GetString("layoutDir"))
 }
+
 func TestLoadMultiConfig(t *testing.T) {
 	t.Parallel()
 
+	assert := require.New(t)
+
 	// Add a random config variable for testing.
 	// side = page in Norwegian.
 	configContentBase := `
@@ -62,6 +67,264 @@ func TestLoadMultiConfig(t *testing.T) {
 	cfg, err := LoadConfig(ConfigSourceDescriptor{Fs: mm, Name: "base.toml,override.toml"})
 	require.NoError(t, err)
 
-	assert.Equal(t, "top", cfg.GetString("paginatePath"))
-	assert.Equal(t, "same", cfg.GetString("DontChange"))
+	assert.Equal("top", cfg.GetString("paginatePath"))
+	assert.Equal("same", cfg.GetString("DontChange"))
+}
+
+func TestLoadConfigFromTheme(t *testing.T) {
+	t.Parallel()
+
+	assert := require.New(t)
+
+	mainConfigBasic := `
+theme = "test-theme"
+baseURL = "https://example.com/"
+
+`
+	mainConfig := `
+theme = "test-theme"
+baseURL = "https://example.com/"
+
+[frontmatter]
+date = ["date","publishDate"]
+
+[params]
+p1 = "p1 main"
+p2 = "p2 main"
+
+[mediaTypes]
+[mediaTypes."text/m1"]
+suffix = "m1main"
+
+[outputFormats.o1]
+mediaType = "text/m1"
+baseName = "o1main"
+
+[languages]
+[languages.en]
+languageName = "English"
+[languages.en.params]
+pl1 = "p1-en-main"
+[languages.nb]
+languageName = "Norsk"
+[languages.nb.params]
+pl1 = "p1-nb-main"
+
+[[menu.main]]
+name = "menu-main-main"
+	
+`
+
+	themeConfig := `
+baseURL = "http://bep.is/"
+
+# Can not be set in theme.
+[frontmatter]
+expiryDate = ["date"]
+
+[params]
+p1 = "p1 theme"
+p2 = "p2 theme"
+p3 = "p3 theme"
+
+[mediaTypes]
+[mediaTypes."text/m1"]
+suffix = "m1theme"
+[mediaTypes."text/m2"]
+suffix = "m2theme"
+
+[outputFormats.o1]
+mediaType = "text/m1"
+baseName = "o1theme"
+[outputFormats.o2]
+mediaType = "text/m2"
+baseName = "o2theme"
+
+[languages]
+[languages.en]
+languageName = "English2"
+[languages.en.params]
+pl1 = "p1-en-theme"
+pl2 = "p2-en-theme"
+[languages.nb]
+languageName = "Norsk2"
+[languages.nb.params]
+pl1 = "p1-nb-theme"
+pl2 = "p2-nb-theme"
+
+[[menu.main]]
+name = "menu-main-theme"
+
+[[menu.thememenu]]
+name = "menu-theme"
+
+`
+
+	// TODO(bep) config watch
+	b := newTestSitesBuilder(t)
+	b.WithConfigFile("toml", mainConfig).WithThemeConfigFile("toml", themeConfig)
+	b.CreateSites().Build(BuildCfg{})
+
+	got := b.Cfg.(*viper.Viper).AllSettings()
+
+	b.AssertObject(`
+map[string]interface {}{
+  "p1": "p1 main",
+  "p2": "p2 main",
+  "p3": "p3 theme",
+  "test-theme": map[string]interface {}{
+    "p1": "p1 theme",
+    "p2": "p2 theme",
+    "p3": "p3 theme",
+  },
+}`, got["params"])
+
+	b.AssertObject(`
+map[string]interface {}{
+  "date": []interface {}{
+    "date",
+    "publishDate",
+  },
+}`, got["frontmatter"])
+
+	b.AssertObject(`
+map[string]interface {}{
+  "text/m1": map[string]interface {}{
+    "suffix": "m1main",
+  },
+  "text/m2": map[string]interface {}{
+    "suffix": "m2theme",
+  },
+}`, got["mediatypes"])
+
+	b.AssertObject(`
+map[string]interface {}{
+  "o1": map[string]interface {}{
+    "basename": "o1main",
+    "mediatype": Type{
+      MainType: "text",
+      SubType: "m1",
+      Suffix: "m1main",
+      Delimiter: ".",
+    },
+  },
+  "o2": map[string]interface {}{
+    "basename": "o2theme",
+    "mediatype": Type{
+      MainType: "text",
+      SubType: "m2",
+      Suffix: "m2theme",
+      Delimiter: ".",
+    },
+  },
+}`, got["outputformats"])
+
+	b.AssertObject(`
+map[string]interface {}{
+  "en": map[string]interface {}{
+    "languagename": "English",
+    "params": map[string]interface {}{
+      "pl1": "p1-en-main",
+      "pl2": "p2-en-theme",
+      "test-theme": map[string]interface {}{
+        "pl1": "p1-en-theme",
+        "pl2": "p2-en-theme",
+      },
+    },
+  },
+  "nb": map[string]interface {}{
+    "languagename": "Norsk",
+    "params": map[string]interface {}{
+      "pl1": "p1-nb-main",
+      "pl2": "p2-nb-theme",
+      "test-theme": map[string]interface {}{
+        "pl1": "p1-nb-theme",
+        "pl2": "p2-nb-theme",
+      },
+    },
+  },
+}
+`, got["languages"])
+
+	b.AssertObject(`
+map[string]interface {}{
+  "main": []interface {}{
+    map[string]interface {}{
+      "name": "menu-main-main",
+    },
+  },
+  "thememenu": []interface {}{
+    map[string]interface {}{
+      "name": "menu-theme",
+    },
+  },
+}
+`, got["menu"])
+
+	assert.Equal("https://example.com/", got["baseurl"])
+
+	// Test variants with only values from theme
+	b = newTestSitesBuilder(t)
+	b.WithConfigFile("toml", mainConfigBasic).WithThemeConfigFile("toml", themeConfig)
+	b.CreateSites().Build(BuildCfg{})
+
+	got = b.Cfg.(*viper.Viper).AllSettings()
+
+	b.AssertObject(`map[string]interface {}{
+  "p1": "p1 theme",
+  "p2": "p2 theme",
+  "p3": "p3 theme",
+  "test-theme": map[string]interface {}{
+    "p1": "p1 theme",
+    "p2": "p2 theme",
+    "p3": "p3 theme",
+  },
+}`, got["params"])
+
+	assert.Nil(got["languages"])
+	b.AssertObject(`
+map[string]interface {}{
+  "text/m1": map[string]interface {}{
+    "suffix": "m1theme",
+  },
+  "text/m2": map[string]interface {}{
+    "suffix": "m2theme",
+  },
+}`, got["mediatypes"])
+
+	b.AssertObject(`
+map[string]interface {}{
+  "o1": map[string]interface {}{
+    "basename": "o1theme",
+    "mediatype": Type{
+      MainType: "text",
+      SubType: "m1",
+      Suffix: "m1theme",
+      Delimiter: ".",
+    },
+  },
+  "o2": map[string]interface {}{
+    "basename": "o2theme",
+    "mediatype": Type{
+      MainType: "text",
+      SubType: "m2",
+      Suffix: "m2theme",
+      Delimiter: ".",
+    },
+  },
+}`, got["outputformats"])
+	b.AssertObject(`
+map[string]interface {}{
+  "main": []interface {}{
+    map[string]interface {}{
+      "name": "menu-main-theme",
+    },
+  },
+  "thememenu": []interface {}{
+    map[string]interface {}{
+      "name": "menu-theme",
+    },
+  },
+}`, got["menu"])
+
 }
diff --git a/hugolib/site.go b/hugolib/site.go
index 2e8898bd6bf..0ffe153e919 100644
--- a/hugolib/site.go
+++ b/hugolib/site.go
@@ -296,6 +296,7 @@ func NewSite(cfg deps.DepsCfg) (*Site, error) {
 // NewSiteDefaultLang creates a new site in the default language.
 // The site will have a template system loaded and ready to use.
 // Note: This is mainly used in single site tests.
+// TODO(bep) test refactor -- remove
 func NewSiteDefaultLang(withTemplate ...func(templ tpl.TemplateHandler) error) (*Site, error) {
 	v := viper.New()
 	if err := loadDefaultSettingsFor(v); err != nil {
@@ -307,6 +308,7 @@ func NewSiteDefaultLang(withTemplate ...func(templ tpl.TemplateHandler) error) (
 // NewEnglishSite creates a new site in English language.
 // The site will have a template system loaded and ready to use.
 // Note: This is mainly used in single site tests.
+// TODO(bep) test refactor -- remove
 func NewEnglishSite(withTemplate ...func(templ tpl.TemplateHandler) error) (*Site, error) {
 	v := viper.New()
 	if err := loadDefaultSettingsFor(v); err != nil {
diff --git a/hugolib/testhelpers_test.go b/hugolib/testhelpers_test.go
index ab23b343cf7..ceadf506b5a 100644
--- a/hugolib/testhelpers_test.go
+++ b/hugolib/testhelpers_test.go
@@ -10,6 +10,8 @@ import (
 	"strings"
 	"text/template"
 
+	"github.com/sanity-io/litter"
+
 	jww "github.com/spf13/jwalterweatherman"
 
 	"github.com/gohugoio/hugo/config"
@@ -37,11 +39,15 @@ type sitesBuilder struct {
 	Fs  *hugofs.Fs
 	T   testing.TB
 
+	dumper litter.Options
+
 	// Aka the Hugo server mode.
 	running bool
 
 	H *HugoSites
 
+	theme string
+
 	// Default toml
 	configFormat string
 
@@ -63,7 +69,13 @@ func newTestSitesBuilder(t testing.TB) *sitesBuilder {
 	v := viper.New()
 	fs := hugofs.NewMem(v)
 
-	return &sitesBuilder{T: t, Fs: fs, configFormat: "toml"}
+	litterOptions := litter.Options{
+		HidePrivateFields: true,
+		StripPackageNames: true,
+		Separator:         " ",
+	}
+
+	return &sitesBuilder{T: t, Fs: fs, configFormat: "toml", dumper: litterOptions}
 }
 
 func (s *sitesBuilder) Running() *sitesBuilder {
@@ -97,6 +109,15 @@ func (s *sitesBuilder) WithConfigFile(format, conf string) *sitesBuilder {
 	return s
 }
 
+func (s *sitesBuilder) WithThemeConfigFile(format, conf string) *sitesBuilder {
+	if s.theme == "" {
+		s.theme = "test-theme"
+	}
+	filename := filepath.Join("themes", s.theme, "config."+format)
+	writeSource(s.T, s.Fs, filename, conf)
+	return s
+}
+
 func (s *sitesBuilder) WithSimpleConfigFile() *sitesBuilder {
 	var config = `
 baseURL = "http://example.com/"
@@ -345,6 +366,16 @@ func (s *sitesBuilder) AssertFileContent(filename string, matches ...string) {
 	}
 }
 
+func (s *sitesBuilder) AssertObject(expected string, object interface{}) {
+	got := s.dumper.Sdump(object)
+	expected = strings.TrimSpace(expected)
+
+	if expected != got {
+		fmt.Println(got)
+		s.Fatalf("expected\n%s\ngot\n%s", expected, got)
+	}
+}
+
 func (s *sitesBuilder) AssertFileContentRe(filename string, matches ...string) {
 	content := readDestination(s.T, s.Fs, filename)
 	for _, match := range matches {