diff --git a/models/user/user.go b/models/user/user.go
index 6143992a2537b..fcfd8a74a18d1 100644
--- a/models/user/user.go
+++ b/models/user/user.go
@@ -201,7 +201,7 @@ func (u *User) BeforeUpdate() {
 // AfterLoad is invoked from XORM after filling all the fields of this object.
 func (u *User) AfterLoad() {
 	if u.Theme == "" {
-		u.Theme = setting.UI.DefaultTheme
+		u.Theme = setting.Config().Theme.DefaultTheme.Value(context.Background())
 	}
 }
 
@@ -663,7 +663,7 @@ func createUser(ctx context.Context, u *User, meta *Meta, createdByAdmin bool, o
 	u.AllowCreateOrganization = setting.Service.DefaultAllowCreateOrganization && !setting.Admin.DisableRegularOrgCreation
 	u.EmailNotificationsPreference = setting.Admin.DefaultEmailNotification
 	u.MaxRepoCreation = -1
-	u.Theme = setting.UI.DefaultTheme
+	u.Theme = setting.Config().Theme.DefaultTheme.Value(ctx)
 	u.IsRestricted = setting.Service.DefaultUserIsRestricted
 	u.IsActive = !(setting.Service.RegisterEmailConfirm || setting.Service.RegisterManualConfirm)
 
diff --git a/models/user/user_test.go b/models/user/user_test.go
index 4201ec4816c86..2ae3565832c7c 100644
--- a/models/user/user_test.go
+++ b/models/user/user_test.go
@@ -276,7 +276,7 @@ func TestCreateUserInvalidEmail(t *testing.T) {
 		Email:              "GiteaBot@gitea.io\r\n",
 		Passwd:             ";p['////..-++']",
 		IsAdmin:            false,
-		Theme:              setting.UI.DefaultTheme,
+		Theme:              setting.Config().Theme.DefaultTheme.Value(t.Context()),
 		MustChangePassword: false,
 	}
 
diff --git a/modules/fileicon/render.go b/modules/fileicon/render.go
index 8ed86b9ac0eb9..cb5d7627edaf5 100644
--- a/modules/fileicon/render.go
+++ b/modules/fileicon/render.go
@@ -4,6 +4,7 @@
 package fileicon
 
 import (
+	"context"
 	"html/template"
 	"strings"
 
@@ -34,7 +35,7 @@ func (p *RenderedIconPool) RenderToHTML() template.HTML {
 }
 
 func RenderEntryIconHTML(renderedIconPool *RenderedIconPool, entry *EntryInfo) template.HTML {
-	if setting.UI.FileIconTheme == "material" {
+	if setting.Config().Theme.DefaultFileIconTheme.Value(context.Background()) == "material" {
 		return DefaultMaterialIconProvider().EntryIconHTML(renderedIconPool, entry)
 	}
 	return BasicEntryIconHTML(entry)
diff --git a/modules/setting/config.go b/modules/setting/config.go
index 4c5d2df7d8a01..42d9702e3bcf0 100644
--- a/modules/setting/config.go
+++ b/modules/setting/config.go
@@ -10,6 +10,11 @@ import (
 	"code.gitea.io/gitea/modules/setting/config"
 )
 
+type ThemeStruct struct {
+	DefaultTheme         *config.Value[string]
+	DefaultFileIconTheme *config.Value[string]
+}
+
 type PictureStruct struct {
 	DisableGravatar       *config.Value[bool]
 	EnableFederatedAvatar *config.Value[bool]
@@ -53,6 +58,7 @@ type RepositoryStruct struct {
 }
 
 type ConfigStruct struct {
+	Theme      *ThemeStruct
 	Picture    *PictureStruct
 	Repository *RepositoryStruct
 }
@@ -65,6 +71,10 @@ var (
 func initDefaultConfig() {
 	config.SetCfgSecKeyGetter(&cfgSecKeyGetter{})
 	defaultConfig = &ConfigStruct{
+		Theme: &ThemeStruct{
+			DefaultTheme:         config.ValueJSON[string]("theme.default_theme").WithFileConfig(config.CfgSecKey{Sec: "ui", Key: "DEFAULT_THEME"}).WithDefault("gitea-auto"),
+			DefaultFileIconTheme: config.ValueJSON[string]("theme.default_file_icon_theme").WithFileConfig(config.CfgSecKey{Sec: "ui", Key: "FILE_ICON_THEME"}).WithDefault("material"),
+		},
 		Picture: &PictureStruct{
 			DisableGravatar:       config.ValueJSON[bool]("picture.disable_gravatar").WithFileConfig(config.CfgSecKey{Sec: "picture", Key: "DISABLE_GRAVATAR"}),
 			EnableFederatedAvatar: config.ValueJSON[bool]("picture.enable_federated_avatar").WithFileConfig(config.CfgSecKey{Sec: "picture", Key: "ENABLE_FEDERATED_AVATAR"}),
diff --git a/modules/setting/ui.go b/modules/setting/ui.go
index 3d9c916bf7f72..330edc2691789 100644
--- a/modules/setting/ui.go
+++ b/modules/setting/ui.go
@@ -26,9 +26,7 @@ var UI = struct {
 	MaxDisplayFileSize      int64
 	ShowUserEmail           bool
 	DefaultShowFullName     bool
-	DefaultTheme            string
 	Themes                  []string
-	FileIconTheme           string
 	Reactions               []string
 	ReactionsLookup         container.Set[string] `ini:"-"`
 	CustomEmojis            []string
@@ -84,8 +82,6 @@ var UI = struct {
 	CodeCommentLines:        4,
 	ReactionMaxUserNum:      10,
 	MaxDisplayFileSize:      8388608,
-	DefaultTheme:            `gitea-auto`,
-	FileIconTheme:           `material`,
 	Reactions:               []string{`+1`, `-1`, `laugh`, `hooray`, `confused`, `heart`, `rocket`, `eyes`},
 	CustomEmojis:            []string{`git`, `gitea`, `codeberg`, `gitlab`, `github`, `gogs`},
 	CustomEmojisMap:         map[string]string{"git": ":git:", "gitea": ":gitea:", "codeberg": ":codeberg:", "gitlab": ":gitlab:", "github": ":github:", "gogs": ":gogs:"},
diff --git a/modules/structs/settings.go b/modules/structs/settings.go
index 403afda9ff5bc..02a5e83b69d8e 100644
--- a/modules/structs/settings.go
+++ b/modules/structs/settings.go
@@ -23,6 +23,8 @@ type GeneralRepoSettings struct {
 type GeneralUISettings struct {
 	// DefaultTheme is the default UI theme
 	DefaultTheme string `json:"default_theme"`
+	// DefaultFileIconTheme is the default file icon theme
+	DefaultFileIconTheme string `json:"default_file_icon_theme"`
 	// AllowedReactions contains the list of allowed emoji reactions
 	AllowedReactions []string `json:"allowed_reactions"`
 	// CustomEmojis contains the list of custom emojis
diff --git a/modules/templates/helper.go b/modules/templates/helper.go
index e454bce4bd3c2..7d66cb4e45ec6 100644
--- a/modules/templates/helper.go
+++ b/modules/templates/helper.go
@@ -5,6 +5,7 @@
 package templates
 
 import (
+	"context"
 	"fmt"
 	"html/template"
 	"net/url"
@@ -218,13 +219,14 @@ func evalTokens(tokens ...any) (any, error) {
 }
 
 func userThemeName(user *user_model.User) string {
+	defaultTheme := setting.Config().Theme.DefaultTheme.Value(context.Background())
 	if user == nil || user.Theme == "" {
-		return setting.UI.DefaultTheme
+		return defaultTheme
 	}
 	if webtheme.IsThemeAvailable(user.Theme) {
 		return user.Theme
 	}
-	return setting.UI.DefaultTheme
+	return defaultTheme
 }
 
 func isQueryParamEmpty(v any) bool {
diff --git a/options/locale/locale_en-US.ini b/options/locale/locale_en-US.ini
index b3eb7b1f4a4fd..78d2ce5e9c0dd 100644
--- a/options/locale/locale_en-US.ini
+++ b/options/locale/locale_en-US.ini
@@ -3428,6 +3428,9 @@ config.session_life_time = Session Life Time
 config.https_only = HTTPS Only
 config.cookie_life_time = Cookie Life Time
 
+config.theme = Theme Configuration
+config.default_theme = Default Theme
+config.default_file_icon_theme = Default File Icon Theme
 config.picture_config = Picture and Avatar Configuration
 config.picture_service = Picture Service
 config.disable_gravatar = Disable Gravatar
diff --git a/routers/api/v1/settings/settings.go b/routers/api/v1/settings/settings.go
index 94fbadeab0188..23d24b0cb9c19 100644
--- a/routers/api/v1/settings/settings.go
+++ b/routers/api/v1/settings/settings.go
@@ -22,9 +22,10 @@ func GetGeneralUISettings(ctx *context.APIContext) {
 	//   "200":
 	//     "$ref": "#/responses/GeneralUISettings"
 	ctx.JSON(http.StatusOK, api.GeneralUISettings{
-		DefaultTheme:     setting.UI.DefaultTheme,
-		AllowedReactions: setting.UI.Reactions,
-		CustomEmojis:     setting.UI.CustomEmojis,
+		DefaultTheme:         setting.Config().Theme.DefaultTheme.Value(ctx),
+		DefaultFileIconTheme: setting.Config().Theme.DefaultFileIconTheme.Value(ctx),
+		AllowedReactions:     setting.UI.Reactions,
+		CustomEmojis:         setting.UI.CustomEmojis,
 	})
 }
 
diff --git a/routers/web/admin/config.go b/routers/web/admin/config.go
index 774b31ab9842a..421ff9cf989b4 100644
--- a/routers/web/admin/config.go
+++ b/routers/web/admin/config.go
@@ -21,6 +21,7 @@ import (
 	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/services/context"
 	"code.gitea.io/gitea/services/mailer"
+	"code.gitea.io/gitea/services/webtheme"
 
 	"gitea.com/go-chi/session"
 )
@@ -192,6 +193,8 @@ func ConfigSettings(ctx *context.Context) {
 	ctx.Data["PageIsAdminConfig"] = true
 	ctx.Data["PageIsAdminConfigSettings"] = true
 	ctx.Data["DefaultOpenWithEditorAppsString"] = setting.DefaultOpenWithEditorApps().ToTextareaString()
+	ctx.Data["AvailableThemes"] = webtheme.GetAvailableThemes()
+	ctx.Data["AvailableFileIconThemes"] = []string{"material", "basic"}
 	ctx.HTML(http.StatusOK, tplConfigSettings)
 }
 
@@ -231,6 +234,8 @@ func ChangeConfig(ctx *context.Context) {
 		return json.Marshal(openWithEditorApps)
 	}
 	marshallers := map[string]func(string) ([]byte, error){
+		cfg.Theme.DefaultTheme.DynKey():            marshalString(cfg.Theme.DefaultTheme.DefaultValue()),
+		cfg.Theme.DefaultFileIconTheme.DynKey():    marshalString(cfg.Theme.DefaultFileIconTheme.DefaultValue()),
 		cfg.Picture.DisableGravatar.DynKey():       marshalBool,
 		cfg.Picture.EnableFederatedAvatar.DynKey(): marshalBool,
 		cfg.Repository.OpenWithEditorApps.DynKey(): marshalOpenWithApps,
diff --git a/services/user/user_test.go b/services/user/user_test.go
index 48852b4cb9a39..64543d6c4e3f9 100644
--- a/services/user/user_test.go
+++ b/services/user/user_test.go
@@ -88,7 +88,7 @@ func TestCreateUser(t *testing.T) {
 		Email:              "GiteaBot@gitea.io",
 		Passwd:             ";p['////..-++']",
 		IsAdmin:            false,
-		Theme:              setting.UI.DefaultTheme,
+		Theme:              setting.Config().Theme.DefaultTheme.Value(t.Context()),
 		MustChangePassword: false,
 	}
 
diff --git a/services/webtheme/webtheme.go b/services/webtheme/webtheme.go
index 4e89d6dbac13a..54ad7e260cc48 100644
--- a/services/webtheme/webtheme.go
+++ b/services/webtheme/webtheme.go
@@ -4,6 +4,7 @@
 package webtheme
 
 import (
+	"context"
 	"regexp"
 	"sort"
 	"strings"
@@ -107,19 +108,20 @@ func parseThemeMetaInfo(fileName, cssContent string) *ThemeMetaInfo {
 
 func initThemes() {
 	availableThemes = nil
+	defaultTheme := setting.Config().Theme.DefaultTheme.Value(context.Background())
 	defer func() {
 		availableThemeInternalNames = container.Set[string]{}
 		for _, theme := range availableThemes {
 			availableThemeInternalNames.Add(theme.InternalName)
 		}
-		if !availableThemeInternalNames.Contains(setting.UI.DefaultTheme) {
-			setting.LogStartupProblem(1, log.ERROR, "Default theme %q is not available, please correct the '[ui].DEFAULT_THEME' setting in the config file", setting.UI.DefaultTheme)
+		if !availableThemeInternalNames.Contains(defaultTheme) {
+			setting.LogStartupProblem(1, log.ERROR, "Default theme %q is not available, please correct the '[ui].DEFAULT_THEME' setting in the config file", defaultTheme)
 		}
 	}()
 	cssFiles, err := public.AssetFS().ListFiles("/assets/css")
 	if err != nil {
 		log.Error("Failed to list themes: %v", err)
-		availableThemes = []*ThemeMetaInfo{defaultThemeMetaInfoByInternalName(setting.UI.DefaultTheme)}
+		availableThemes = []*ThemeMetaInfo{defaultThemeMetaInfoByInternalName(defaultTheme)}
 		return
 	}
 	var foundThemes []*ThemeMetaInfo
@@ -144,14 +146,14 @@ func initThemes() {
 		availableThemes = foundThemes
 	}
 	sort.Slice(availableThemes, func(i, j int) bool {
-		if availableThemes[i].InternalName == setting.UI.DefaultTheme {
+		if availableThemes[i].InternalName == defaultTheme {
 			return true
 		}
 		return availableThemes[i].DisplayName < availableThemes[j].DisplayName
 	})
 	if len(availableThemes) == 0 {
 		setting.LogStartupProblem(1, log.ERROR, "No theme candidate in asset files, but Gitea requires there should be at least one usable theme")
-		availableThemes = []*ThemeMetaInfo{defaultThemeMetaInfoByInternalName(setting.UI.DefaultTheme)}
+		availableThemes = []*ThemeMetaInfo{defaultThemeMetaInfoByInternalName(defaultTheme)}
 	}
 }
 
diff --git a/templates/admin/config_settings/config_settings.tmpl b/templates/admin/config_settings/config_settings.tmpl
index 1ef764a58bac5..d8cfc96d26971 100644
--- a/templates/admin/config_settings/config_settings.tmpl
+++ b/templates/admin/config_settings/config_settings.tmpl
@@ -1,5 +1,7 @@
 {{template "admin/layout_head" (dict "ctxData" . "pageClass" "admin config")}}
 
+{{template "admin/config_settings/theme" .}}
+
 {{template "admin/config_settings/avatars" .}}
 
 {{template "admin/config_settings/repository" .}}
diff --git a/templates/admin/config_settings/theme.tmpl b/templates/admin/config_settings/theme.tmpl
new file mode 100644
index 0000000000000..7ed2bb9ed5501
--- /dev/null
+++ b/templates/admin/config_settings/theme.tmpl
@@ -0,0 +1,36 @@
+<h4 class="ui top attached header">
+	{{ctx.Locale.Tr "admin.config.theme"}}
+</h4>
+<div class="ui attached table segment dropdown-container">
+	<dl class="admin-dl-horizontal">
+		<dt>{{ctx.Locale.Tr "admin.config.default_theme"}}</dt>
+		<dd>
+			<div class="ui selection dropdown js-theme-config-dropdown" data-config-key="theme.default_theme">
+				{{svg "octicon-triangle-down" 14 "dropdown icon"}}
+				<div class="text">
+					<strong>{{$.SystemConfig.Theme.DefaultTheme.Value ctx}}</strong>
+				</div>
+				<div class="menu">
+					{{range .AvailableThemes}}
+						<div class="{{if eq ($.SystemConfig.Theme.DefaultTheme.Value ctx) .DisplayName}}active selected {{end}}item" data-value="{{.DisplayName}}">{{.DisplayName}}</div>
+					{{end}}
+				</div>
+			</div>
+		</dd>
+		<div class="divider"></div>
+		<dt>{{ctx.Locale.Tr "admin.config.default_file_icon_theme"}}</dt>
+		<dd>
+			<div class="ui selection dropdown js-theme-config-dropdown" data-config-key="theme.default_file_icon_theme">
+				{{svg "octicon-triangle-down" 14 "dropdown icon"}}
+				<div class="text">
+					<strong>{{$.SystemConfig.Theme.DefaultFileIconTheme.Value ctx}}</strong>
+				</div>
+				<div class="menu">
+					{{range .AvailableFileIconThemes}}
+						<div class="{{if eq ($.SystemConfig.Theme.DefaultFileIconTheme.Value ctx) .}}active selected {{end}}item" data-value="{{.}}">{{.}}</div>
+					{{end}}
+				</div>
+			</div>
+		</dd>
+	</dl>
+</div>
diff --git a/templates/swagger/v1_json.tmpl b/templates/swagger/v1_json.tmpl
index 77a622cb63546..75e6e28f5d73f 100644
--- a/templates/swagger/v1_json.tmpl
+++ b/templates/swagger/v1_json.tmpl
@@ -25251,6 +25251,11 @@
           },
           "x-go-name": "CustomEmojis"
         },
+        "default_file_icon_theme": {
+          "description": "DefaultFileIconTheme is the default file icon theme",
+          "type": "string",
+          "x-go-name": "DefaultFileIconTheme"
+        },
         "default_theme": {
           "description": "DefaultTheme is the default UI theme",
           "type": "string",
diff --git a/tests/integration/repo_test.go b/tests/integration/repo_test.go
index d12addb1275db..6dcc69ebee41b 100644
--- a/tests/integration/repo_test.go
+++ b/tests/integration/repo_test.go
@@ -14,10 +14,12 @@ import (
 	"time"
 
 	repo_model "code.gitea.io/gitea/models/repo"
+	system_model "code.gitea.io/gitea/models/system"
 	"code.gitea.io/gitea/models/unit"
 	"code.gitea.io/gitea/models/unittest"
 	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/setting/config"
 	"code.gitea.io/gitea/modules/test"
 	"code.gitea.io/gitea/modules/util"
 	repo_service "code.gitea.io/gitea/services/repository"
@@ -223,7 +225,13 @@ func testViewRepo1CloneLinkAuthorized(t *testing.T) {
 
 func testViewRepoWithSymlinks(t *testing.T) {
 	defer tests.PrintCurrentTest(t)()
-	defer test.MockVariableValue(&setting.UI.FileIconTheme, "basic")()
+	defer func() {
+		err := system_model.SetSettings(t.Context(), map[string]string{
+			setting.Config().Theme.DefaultFileIconTheme.DynKey(): "basic",
+		})
+		assert.NoError(t, err)
+		config.GetDynGetter().InvalidateCache()
+	}()
 	session := loginUser(t, "user2")
 
 	req := NewRequest(t, "GET", "/user2/repo20.git")
diff --git a/web_src/css/admin.css b/web_src/css/admin.css
index cda38c6dddf22..a734125a30d7e 100644
--- a/web_src/css/admin.css
+++ b/web_src/css/admin.css
@@ -15,6 +15,8 @@
 .admin dl.admin-dl-horizontal dd {
   line-height: var(--line-height-default);
   padding: 5px 0;
+  display: flex;
+  align-items: center;
 }
 
 .admin dl.admin-dl-horizontal dt {
@@ -39,6 +41,10 @@
   overflow-x: auto; /* if the screen width is small, many wide tables (eg: user list) need scroll bars */
 }
 
+.admin .ui.table.segment.dropdown-container {
+  overflow: visible; /* allow dropdown menus to extend beyond container boundaries */
+}
+
 .admin .table th {
   white-space: nowrap;
 }
diff --git a/web_src/js/features/admin/config.ts b/web_src/js/features/admin/config.ts
index 16d7a2426f978..2950d78f1ba25 100644
--- a/web_src/js/features/admin/config.ts
+++ b/web_src/js/features/admin/config.ts
@@ -1,5 +1,6 @@
 import {showTemporaryTooltip} from '../../modules/tippy.ts';
 import {POST} from '../../modules/fetch.ts';
+import {fomanticQuery} from '../../modules/fomantic/base.ts';
 
 const {appSubUrl} = window.config;
 
@@ -21,4 +22,28 @@ export function initAdminConfigs(): void {
       }
     });
   }
+
+  // Handle theme config dropdowns
+  for (const el of elAdminConfig.querySelectorAll('.js-theme-config-dropdown')) {
+    fomanticQuery(el).dropdown({
+      async onChange(value: string, _text: string, _$item: any) {
+        if (!value) return;
+
+        const configKey = this.getAttribute('data-config-key');
+        if (!configKey) return;
+
+        try {
+          const resp = await POST(`${appSubUrl}/-/admin/config`, {
+            data: new URLSearchParams({key: configKey, value}),
+          });
+          const json: Record<string, any> = await resp.json();
+          if (json.errorMessage) throw new Error(json.errorMessage);
+        } catch (ex) {
+          showTemporaryTooltip(this, ex.toString());
+          // Revert the dropdown to the previous value on error
+          fomanticQuery(el).dropdown('restore defaults');
+        }
+      },
+    });
+  }
 }