diff --git a/webview-ui/src/components/chat/ModeSelector.tsx b/webview-ui/src/components/chat/ModeSelector.tsx
index 93dd2f1f4f..ef8ea2dddc 100644
--- a/webview-ui/src/components/chat/ModeSelector.tsx
+++ b/webview-ui/src/components/chat/ModeSelector.tsx
@@ -7,7 +7,7 @@ import { IconButton } from "./IconButton"
 import { vscode } from "@/utils/vscode"
 import { useExtensionState } from "@/context/ExtensionStateContext"
 import { useAppTranslation } from "@/i18n/TranslationContext"
-import { Mode, getAllModes } from "@roo/modes"
+import { Mode, getAllModes, isCustomMode } from "@roo/modes"
 import { ModeConfig, CustomModePrompts } from "@roo-code/types"
 import { telemetryClient } from "@/utils/TelemetryClient"
 import { TelemetryEventName } from "@roo-code/types"
@@ -16,6 +16,32 @@ import { Fzf } from "fzf"
 // Minimum number of modes required to show search functionality
 const SEARCH_THRESHOLD = 6
 
+// Helper function to get the source of a custom mode
+function getModeSource(mode: ModeConfig, customModes?: ModeConfig[]): "global" | "project" | null {
+	if (!isCustomMode(mode.slug, customModes)) {
+		return null // Built-in mode, no source indicator needed
+	}
+
+	// Find the mode in customModes to get its source
+	const customMode = customModes?.find((m) => m.slug === mode.slug)
+	return customMode?.source || "global" // Default to global if source is not specified
+}
+
+// Helper function to get the display text for mode source
+function getSourceDisplayText(
+	source: "global" | "project" | null,
+	t: (key: string) => string,
+	short: boolean = false,
+): string {
+	if (!source) return ""
+
+	if (short) {
+		return source === "global" ? t("chat:modeSelector.globalShort") : t("chat:modeSelector.projectShort")
+	}
+
+	return source === "global" ? t("chat:modeSelector.global") : t("chat:modeSelector.project")
+}
+
 interface ModeSelectorProps {
 	value: Mode
 	onChange: (value: Mode) => void
@@ -159,6 +185,10 @@ export const ModeSelector = ({
 	// Combine instruction text for tooltip
 	const instructionText = `${t("chat:modeSelector.description")} ${modeShortcutText}`
 
+	// Get source indicator for selected mode
+	const selectedModeSource = selectedMode ? getModeSource(selectedMode, customModes) : null
+	const selectedModeSourceText = getSourceDisplayText(selectedModeSource, t, false)
+
 	const trigger = (
 		<PopoverTrigger
 			disabled={disabled}
@@ -176,7 +206,12 @@ export const ModeSelector = ({
 					: null,
 			)}>
 			<ChevronUp className="pointer-events-none opacity-80 flex-shrink-0 size-3" />
-			<span className="truncate">{selectedMode?.name || ""}</span>
+			<span className="truncate">
+				{selectedMode?.name || ""}
+				{selectedModeSourceText && (
+					<span className="text-vscode-descriptionForeground ml-1">({selectedModeSourceText})</span>
+				)}
+			</span>
 		</PopoverTrigger>
 	)
 
@@ -225,29 +260,41 @@ export const ModeSelector = ({
 							</div>
 						) : (
 							<div className="py-1">
-								{filteredModes.map((mode) => (
-									<div
-										key={mode.slug}
-										onClick={() => handleSelect(mode.slug)}
-										className={cn(
-											"px-3 py-1.5 text-sm cursor-pointer flex items-center",
-											"hover:bg-vscode-list-hoverBackground",
-											mode.slug === value
-												? "bg-vscode-list-activeSelectionBackground text-vscode-list-activeSelectionForeground"
-												: "",
-										)}
-										data-testid="mode-selector-item">
-										<div className="flex-1 min-w-0">
-											<div className="font-bold truncate">{mode.name}</div>
-											{mode.description && (
-												<div className="text-xs text-vscode-descriptionForeground truncate">
-													{mode.description}
-												</div>
+								{filteredModes.map((mode) => {
+									const modeSource = getModeSource(mode, customModes)
+									const sourceShortText = getSourceDisplayText(modeSource, t, true)
+
+									return (
+										<div
+											key={mode.slug}
+											onClick={() => handleSelect(mode.slug)}
+											className={cn(
+												"px-3 py-1.5 text-sm cursor-pointer flex items-center",
+												"hover:bg-vscode-list-hoverBackground",
+												mode.slug === value
+													? "bg-vscode-list-activeSelectionBackground text-vscode-list-activeSelectionForeground"
+													: "",
 											)}
+											data-testid="mode-selector-item">
+											<div className="flex-1 min-w-0">
+												<div className="font-bold truncate flex items-center gap-1.5">
+													{mode.name}
+													{sourceShortText && (
+														<span className="text-xs text-vscode-descriptionForeground font-normal">
+															({sourceShortText})
+														</span>
+													)}
+												</div>
+												{mode.description && (
+													<div className="text-xs text-vscode-descriptionForeground truncate">
+														{mode.description}
+													</div>
+												)}
+											</div>
+											{mode.slug === value && <Check className="ml-auto size-4 p-0.5" />}
 										</div>
-										{mode.slug === value && <Check className="ml-auto size-4 p-0.5" />}
-									</div>
-								))}
+									)
+								})}
 							</div>
 						)}
 					</div>
diff --git a/webview-ui/src/components/chat/__tests__/ModeSelector.spec.tsx b/webview-ui/src/components/chat/__tests__/ModeSelector.spec.tsx
index a829168893..ff97306165 100644
--- a/webview-ui/src/components/chat/__tests__/ModeSelector.spec.tsx
+++ b/webview-ui/src/components/chat/__tests__/ModeSelector.spec.tsx
@@ -199,4 +199,140 @@ describe("ModeSelector", () => {
 		const infoIcon = document.querySelector(".codicon-info")
 		expect(infoIcon).toBeInTheDocument()
 	})
+
+	test("shows source indicators for custom modes", () => {
+		// Set up mock to return custom modes with source
+		mockModes = [
+			{
+				slug: "custom-global",
+				name: "Custom Global Mode",
+				description: "A global custom mode",
+				roleDefinition: "Role definition",
+				groups: ["read", "edit"] as const,
+				source: "global",
+			},
+			{
+				slug: "custom-project",
+				name: "Custom Project Mode",
+				description: "A project custom mode",
+				roleDefinition: "Role definition",
+				groups: ["read", "edit"] as const,
+				source: "project",
+			},
+			{
+				slug: "code",
+				name: "Code Mode",
+				description: "Built-in code mode",
+				roleDefinition: "Role definition",
+				groups: ["read", "edit"] as const,
+			},
+		]
+
+		const customModes: ModeConfig[] = [
+			{
+				slug: "custom-global",
+				name: "Custom Global Mode",
+				description: "A global custom mode",
+				roleDefinition: "Role definition",
+				groups: ["read", "edit"],
+				source: "global",
+			},
+			{
+				slug: "custom-project",
+				name: "Custom Project Mode",
+				description: "A project custom mode",
+				roleDefinition: "Role definition",
+				groups: ["read", "edit"],
+				source: "project",
+			},
+		]
+
+		render(
+			<ModeSelector
+				value={"custom-global" as Mode}
+				onChange={vi.fn()}
+				modeShortcutText="Ctrl+M"
+				customModes={customModes}
+			/>,
+		)
+
+		// Click to open the popover
+		fireEvent.click(screen.getByTestId("mode-selector-trigger"))
+
+		// Check that custom modes show source indicators in dropdown
+		const modeItems = screen.getAllByTestId("mode-selector-item")
+
+		// Find the custom modes in the dropdown
+		const globalModeItem = modeItems.find((item) => item.textContent?.includes("Custom Global Mode"))
+		const projectModeItem = modeItems.find((item) => item.textContent?.includes("Custom Project Mode"))
+		const builtinModeItem = modeItems.find((item) => item.textContent?.includes("Code Mode"))
+
+		// Custom modes should show source indicators
+		expect(globalModeItem?.textContent).toContain("(chat:modeSelector.globalShort)")
+		expect(projectModeItem?.textContent).toContain("(chat:modeSelector.projectShort)")
+
+		// Built-in mode should not show source indicator
+		expect(builtinModeItem?.textContent).not.toContain("(chat:modeSelector.globalShort)")
+		expect(builtinModeItem?.textContent).not.toContain("(chat:modeSelector.projectShort)")
+	})
+
+	test("shows source indicator in selected mode button", () => {
+		// Set up mock to return custom modes with source
+		mockModes = [
+			{
+				slug: "custom-project",
+				name: "Custom Project Mode",
+				description: "A project custom mode",
+				roleDefinition: "Role definition",
+				groups: ["read", "edit"] as const,
+				source: "project",
+			},
+		]
+
+		const customModes: ModeConfig[] = [
+			{
+				slug: "custom-project",
+				name: "Custom Project Mode",
+				description: "A project custom mode",
+				roleDefinition: "Role definition",
+				groups: ["read", "edit"],
+				source: "project",
+			},
+		]
+
+		render(
+			<ModeSelector
+				value={"custom-project" as Mode}
+				onChange={vi.fn()}
+				modeShortcutText="Ctrl+M"
+				customModes={customModes}
+			/>,
+		)
+
+		// Check that the trigger button shows the source indicator
+		const trigger = screen.getByTestId("mode-selector-trigger")
+		expect(trigger.textContent).toContain("Custom Project Mode")
+		expect(trigger.textContent).toContain("(chat:modeSelector.project)")
+	})
+
+	test("does not show source indicator for built-in modes", () => {
+		// Set up mock to return only built-in modes
+		mockModes = [
+			{
+				slug: "code",
+				name: "Code Mode",
+				description: "Built-in code mode",
+				roleDefinition: "Role definition",
+				groups: ["read", "edit"] as const,
+			},
+		]
+
+		render(<ModeSelector value={"code" as Mode} onChange={vi.fn()} modeShortcutText="Ctrl+M" customModes={[]} />)
+
+		// Check that the trigger button does not show source indicator
+		const trigger = screen.getByTestId("mode-selector-trigger")
+		expect(trigger.textContent).toContain("Code Mode")
+		expect(trigger.textContent).not.toContain("(Global)")
+		expect(trigger.textContent).not.toContain("(Project)")
+	})
 })
diff --git a/webview-ui/src/i18n/locales/de/chat.json b/webview-ui/src/i18n/locales/de/chat.json
index 36c03c9309..e22e4faae4 100644
--- a/webview-ui/src/i18n/locales/de/chat.json
+++ b/webview-ui/src/i18n/locales/de/chat.json
@@ -118,7 +118,11 @@
 		"settings": "Modus-Einstellungen",
 		"description": "Spezialisierte Personas, die Roos Verhalten anpassen.",
 		"searchPlaceholder": "Modi suchen...",
-		"noResults": "Keine Ergebnisse gefunden"
+		"noResults": "Keine Ergebnisse gefunden",
+		"global": "Global",
+		"project": "Projekt",
+		"globalShort": "G",
+		"projectShort": "P"
 	},
 	"errorReadingFile": "Fehler beim Lesen der Datei:",
 	"noValidImages": "Keine gültigen Bilder wurden verarbeitet",
diff --git a/webview-ui/src/i18n/locales/en/chat.json b/webview-ui/src/i18n/locales/en/chat.json
index b33ddd4ab4..33a11a2d7f 100644
--- a/webview-ui/src/i18n/locales/en/chat.json
+++ b/webview-ui/src/i18n/locales/en/chat.json
@@ -120,7 +120,11 @@
 		"settings": "Mode Settings",
 		"description": "Specialized personas that tailor Roo's behavior.",
 		"searchPlaceholder": "Search modes...",
-		"noResults": "No results found"
+		"noResults": "No results found",
+		"global": "Global",
+		"project": "Project",
+		"globalShort": "G",
+		"projectShort": "P"
 	},
 	"enhancePromptDescription": "The 'Enhance Prompt' button helps improve your prompt by providing additional context, clarification, or rephrasing. Try typing a prompt in here and clicking the button again to see how it works.",
 	"addImages": "Add images to message",
diff --git a/webview-ui/src/i18n/locales/es/chat.json b/webview-ui/src/i18n/locales/es/chat.json
index 156af85012..a1237b5861 100644
--- a/webview-ui/src/i18n/locales/es/chat.json
+++ b/webview-ui/src/i18n/locales/es/chat.json
@@ -118,7 +118,11 @@
 		"settings": "Configuración de Modos",
 		"description": "Personalidades especializadas que adaptan el comportamiento de Roo.",
 		"searchPlaceholder": "Buscar modos...",
-		"noResults": "No se encontraron resultados"
+		"noResults": "No se encontraron resultados",
+		"global": "Global",
+		"project": "Proyecto",
+		"globalShort": "G",
+		"projectShort": "P"
 	},
 	"errorReadingFile": "Error al leer el archivo:",
 	"noValidImages": "No se procesaron imágenes válidas",
diff --git a/webview-ui/src/i18n/locales/fr/chat.json b/webview-ui/src/i18n/locales/fr/chat.json
index 959db06b39..cab2746290 100644
--- a/webview-ui/src/i18n/locales/fr/chat.json
+++ b/webview-ui/src/i18n/locales/fr/chat.json
@@ -118,7 +118,11 @@
 		"settings": "Paramètres des Modes",
 		"description": "Personas spécialisés qui adaptent le comportement de Roo.",
 		"searchPlaceholder": "Rechercher des modes...",
-		"noResults": "Aucun résultat trouvé"
+		"noResults": "Aucun résultat trouvé",
+		"global": "Global",
+		"project": "Projet",
+		"globalShort": "G",
+		"projectShort": "P"
 	},
 	"errorReadingFile": "Erreur lors de la lecture du fichier :",
 	"noValidImages": "Aucune image valide n'a été traitée",