diff --git a/frontend/src/lib/components/WorkspaceScopeTrigger.svelte b/frontend/src/lib/components/WorkspaceScopeTrigger.svelte
index ac132bdca2..77fe52b421 100644
--- a/frontend/src/lib/components/WorkspaceScopeTrigger.svelte
+++ b/frontend/src/lib/components/WorkspaceScopeTrigger.svelte
@@ -1,5 +1,5 @@
 <script lang="ts">
-	import { userWorkspaces } from '$lib/stores'
+	import { userWorkspaces, type UserWorkspace } from '$lib/stores'
 	import { findWorkspaceRoot } from '$lib/utils/workspaceHierarchy'
 	import { forkAccentStyle } from '$lib/utils/forkColor'
 	import { Badge, Button } from '$lib/components/common'
@@ -24,6 +24,7 @@
 		interactive = true,
 		menuItems = undefined,
 		disableTitle = false,
+		forkableWorkspaces,
 		class: className = ''
 	}: {
 		workspaceId?: string
@@ -55,19 +56,23 @@
 		// Suppress the chip's native `title` so it doesn't double-pop when a
 		// consumer wraps the chip in a richer hover tooltip (e.g. NameIdTooltip).
 		disableTitle?: boolean
+		// Pre-resolved workspace list from a consumer that folded in a
+		// superadmin-visited workspace (see useForkableWorkspaces), so the chip
+		// resolves its name/family for a workspace absent from `$userWorkspaces`.
+		// Omitted consumers fall back to the member-only list.
+		forkableWorkspaces?: UserWorkspace[]
 		class?: string
 	} = $props()
 
-	const root = $derived(findWorkspaceRoot(workspaceId, $userWorkspaces))
-	const currentWs = $derived(
-		workspaceId ? $userWorkspaces.find((w) => w.id === workspaceId) : undefined
-	)
+	const workspaces = $derived(forkableWorkspaces ?? $userWorkspaces)
+	const root = $derived(findWorkspaceRoot(workspaceId, workspaces))
+	const currentWs = $derived(workspaceId ? workspaces.find((w) => w.id === workspaceId) : undefined)
 	const isFork = $derived(!!currentWs && !!root && currentWs.id !== root.id)
 	const showFork = $derived(!!pendingFork || isFork)
 	const name = $derived(pendingFork?.name ?? currentWs?.name ?? workspaceId ?? 'Pick workspace')
 	const parentId = $derived(pendingFork?.parent_workspace_id ?? currentWs?.parent_workspace_id)
 	const parentName = $derived(
-		parentId ? ($userWorkspaces.find((w) => w.id === parentId)?.name ?? parentId) : undefined
+		parentId ? (workspaces.find((w) => w.id === parentId)?.name ?? parentId) : undefined
 	)
 	// The parent segment only appears for a fork of a fork — forking off the
 	// root is the default and doesn't need spelling out.
diff --git a/frontend/src/lib/components/sessions/WorkspaceFamilyPicker.svelte b/frontend/src/lib/components/sessions/WorkspaceFamilyPicker.svelte
index b6b6c4beb0..e1480d5097 100644
--- a/frontend/src/lib/components/sessions/WorkspaceFamilyPicker.svelte
+++ b/frontend/src/lib/components/sessions/WorkspaceFamilyPicker.svelte
@@ -3,9 +3,11 @@
 	import {
 		enterpriseLicense,
 		isPremiumStore,
+		superadmin,
 		userStore,
 		userWorkspaces,
-		workspaceStore
+		workspaceStore,
+		type UserWorkspace
 	} from '$lib/stores'
 	import {
 		findWorkspaceDescendants,
@@ -13,6 +15,7 @@
 		findWorkspaceRoot,
 		buildWorkspaceHierarchy
 	} from '$lib/utils/workspaceHierarchy'
+	import { useForkableWorkspaces } from '$lib/utils/useForkableWorkspaces.svelte'
 	import { canCreateFork } from '$lib/utils/editInFork'
 	import { forkAccentStyle } from '$lib/utils/forkColor'
 	import { getUserExt } from '$lib/user'
@@ -65,6 +68,10 @@
 		// and target href.
 		settingsHref,
 		settingsLabel,
+		// Pre-resolved forkable list from a parent that already computed it (e.g.
+		// WorkspaceScopeHeader), so the superadmin lookup isn't duplicated. Omitted
+		// by standalone consumers, which then resolve it themselves.
+		forkableWorkspaces: forkableWorkspacesProp,
 		trigger
 	}: {
 		selectedId?: string
@@ -77,18 +84,29 @@
 		class?: string
 		settingsHref?: string
 		settingsLabel?: string
+		forkableWorkspaces?: UserWorkspace[]
 		trigger: Snippet<[{ open: boolean }]>
 	} = $props()
 
 	const WM_FORK_PREFIX = 'wm-fork-'
 
 	const effectiveId = $derived(selectedId ?? $workspaceStore ?? undefined)
-	const root = $derived(findWorkspaceRoot(effectiveId, $userWorkspaces))
-	const forks = $derived(root ? findWorkspaceDescendants(root.id, $userWorkspaces) : [])
+	// Resolve the family (see useForkableWorkspaces); skip the lookup when a parent already supplied it.
+	const ownForkable = useForkableWorkspaces({
+		workspaces: () => $userWorkspaces,
+		currentWorkspaceId: () => effectiveId,
+		isSuperadmin: () => !!$superadmin,
+		enabled: () => forkableWorkspacesProp === undefined
+	})
+	const forkableWorkspaces = $derived(forkableWorkspacesProp ?? ownForkable.current)
+	const root = $derived(findWorkspaceRoot(effectiveId, forkableWorkspaces))
+	const forks = $derived(root ? findWorkspaceDescendants(root.id, forkableWorkspaces) : [])
 
 	// The family's canonical dev workspace, if any — still used for gating (a forking-locked root can be
 	// forked via its dev) and as a selectable base with a "dev" badge.
-	const devOfRoot = $derived(root ? findCanonicalDevWorkspace(root.id, $userWorkspaces) : undefined)
+	const devOfRoot = $derived(
+		root ? findCanonicalDevWorkspace(root.id, forkableWorkspaces) : undefined
+	)
 	const createForkLabel = 'Create new fork…'
 	// Candidate bases ("targets") for a new fork: the root plus every fork/dev in the family, so a fork
 	// can itself be the base — i.e. a fork of a fork. Root first, matching the list order below.
@@ -108,7 +126,7 @@
 	// forks of forks under their parent the same way. `forks` is a DFS of descendants (parent before
 	// child), so indenting each row by its depth nests it under its parent.
 	const familyDepths = $derived(
-		new Map(buildWorkspaceHierarchy($userWorkspaces).map((h) => [h.workspace.id, h.depth]))
+		new Map(buildWorkspaceHierarchy(forkableWorkspaces).map((h) => [h.workspace.id, h.depth]))
 	)
 	// Extra left padding (on top of the row's base px-3) to nest a workspace one step per depth level,
 	// matching the sidebar menu's `depth * 16px`.
diff --git a/frontend/src/lib/components/sidebar/WorkspaceScopeHeader.svelte b/frontend/src/lib/components/sidebar/WorkspaceScopeHeader.svelte
index ba6ae625d9..9b34819740 100644
--- a/frontend/src/lib/components/sidebar/WorkspaceScopeHeader.svelte
+++ b/frontend/src/lib/components/sidebar/WorkspaceScopeHeader.svelte
@@ -13,19 +13,28 @@
 	import WorkspaceFamilyPicker from '$lib/components/sessions/WorkspaceFamilyPicker.svelte'
 	import WorkspaceScopeTrigger from '$lib/components/WorkspaceScopeTrigger.svelte'
 	import { findWorkspaceRoot, findWorkspaceDescendants } from '$lib/utils/workspaceHierarchy'
+	import { useForkableWorkspaces } from '$lib/utils/useForkableWorkspaces.svelte'
 
 	let { isCollapsed = false }: { isCollapsed?: boolean } = $props()
 
 	const effectiveId = $derived($workspaceStore ?? undefined)
+	// Resolve once here and pass to the picker + trigger below, avoiding a duplicate lookup (see
+	// useForkableWorkspaces).
+	const forkable = useForkableWorkspaces({
+		workspaces: () => $userWorkspaces,
+		currentWorkspaceId: () => effectiveId,
+		isSuperadmin: () => !!$superadmin
+	})
+	const forkableWorkspaces = $derived(forkable.current)
 	const currentWs = $derived(
-		effectiveId ? $userWorkspaces.find((w) => w.id === effectiveId) : undefined
+		effectiveId ? forkableWorkspaces.find((w) => w.id === effectiveId) : undefined
 	)
 
 	// Fork count surfaces the family's size right on the trigger, hinting that
 	// the muted "root" chip is also the entry point to its forks.
 	const forkCount = $derived.by(() => {
-		const root = findWorkspaceRoot(effectiveId, $userWorkspaces)
-		return root ? findWorkspaceDescendants(root.id, $userWorkspaces).length : 0
+		const root = findWorkspaceRoot(effectiveId, forkableWorkspaces)
+		return root ? findWorkspaceDescendants(root.id, forkableWorkspaces).length : 0
 	})
 	const rootLabel = $derived(`${forkCount} fork${forkCount === 1 ? '' : 's'}`)
 
@@ -50,6 +59,7 @@
 <div class="flex items-center min-w-0 px-2 {isCollapsed ? 'justify-center' : ''} py-0.5 rounded-md">
 	<WorkspaceFamilyPicker
 		selectedId={effectiveId}
+		{forkableWorkspaces}
 		onPick={switchWorkspaceDirect}
 		onRequestCreateFork={openForkModal}
 		{settingsHref}
@@ -59,6 +69,7 @@
 		{#snippet trigger()}
 			<WorkspaceScopeTrigger
 				workspaceId={effectiveId}
+				{forkableWorkspaces}
 				{isCollapsed}
 				{rootLabel}
 				wrap
diff --git a/frontend/src/lib/components/workspaceSettings/CreateWorkspaceInner.svelte b/frontend/src/lib/components/workspaceSettings/CreateWorkspaceInner.svelte
index 5f74da4b80..70fcc5d6fe 100644
--- a/frontend/src/lib/components/workspaceSettings/CreateWorkspaceInner.svelte
+++ b/frontend/src/lib/components/workspaceSettings/CreateWorkspaceInner.svelte
@@ -14,12 +14,13 @@
 	import { validateUsername } from '$lib/utils'
 	import { logoutWithRedirect } from '$lib/logoutKit'
 	import { page } from '$app/state'
-	import { usersWorkspaceStore, userWorkspaces, workspaceStore } from '$lib/stores'
+	import { superadmin, usersWorkspaceStore, userWorkspaces, workspaceStore } from '$lib/stores'
 	import {
 		workspaceIsFork,
 		findWorkspaceRoot,
 		findWorkspaceDescendants
 	} from '$lib/utils/workspaceHierarchy'
+	import { useForkableWorkspaces } from '$lib/utils/useForkableWorkspaces.svelte'
 	import { resource } from 'runed'
 	import { Badge, Button } from '$lib/components/common'
 	import { devBadgeText } from '$lib/utils/devWorkspaceLabel'
@@ -83,10 +84,19 @@
 	// a fork here (rather than the root) yields a fork of a fork.
 	let baseWorkspaceId = $state<string | undefined>(undefined)
 
+	// Base list for forking, folding in a superadmin-visited workspace (see useForkableWorkspaces).
+	const forkable = useForkableWorkspaces({
+		workspaces: () => $userWorkspaces,
+		currentWorkspaceId: () => $workspaceStore,
+		isSuperadmin: () => !!$superadmin,
+		enabled: () => isFork
+	})
+	let forkableWorkspaces = $derived(forkable.current)
+
 	// Base candidates are the current workspace's family: its root first, then every fork/dev under it.
-	let familyRoot = $derived(findWorkspaceRoot($workspaceStore, $userWorkspaces))
+	let familyRoot = $derived(findWorkspaceRoot($workspaceStore, forkableWorkspaces))
 	let baseCandidates = $derived(
-		familyRoot ? [familyRoot, ...findWorkspaceDescendants(familyRoot.id, $userWorkspaces)] : []
+		familyRoot ? [familyRoot, ...findWorkspaceDescendants(familyRoot.id, forkableWorkspaces)] : []
 	)
 	let baseItems = $derived(
 		baseCandidates.map((w) => ({
@@ -112,13 +122,13 @@
 
 	// The dev-workspace option is only offered when forking a root workspace that doesn't already
 	// have one: a workspace gets at most one dev, and dev workspaces don't nest (a dev of a dev).
-	let baseWorkspaceEntry = $derived($userWorkspaces.find((w) => w.id === baseWorkspaceId))
+	let baseWorkspaceEntry = $derived(forkableWorkspaces.find((w) => w.id === baseWorkspaceId))
 	// Require the base workspace to be loaded before treating it as a root: a missing entry must
 	// not read as root (it would offer invalid dev creation while the workspace list is still loading).
 	// `workspaceIsFork` (prefix OR parent) also excludes an orphaned `wm-fork-` workspace, whose parent
 	// FK was set null — it has no parent but is still a fork, so it can't host a dev workspace.
 	let currentIsRoot = $derived(
-		!!baseWorkspaceEntry && !workspaceIsFork(baseWorkspaceId, $userWorkspaces)
+		!!baseWorkspaceEntry && !workspaceIsFork(baseWorkspaceId, forkableWorkspaces)
 	)
 	// Ask the server whether a dev already exists: the caller may not be a member of this prod's dev,
 	// so the client workspace list can't see it and would offer an invalid "create dev" action.
diff --git a/frontend/src/lib/utils/useForkableWorkspaces.svelte.ts b/frontend/src/lib/utils/useForkableWorkspaces.svelte.ts
new file mode 100644
index 0000000000..372d3652a6
--- /dev/null
+++ b/frontend/src/lib/utils/useForkableWorkspaces.svelte.ts
@@ -0,0 +1,50 @@
+import { resource } from 'runed'
+import { WorkspaceService } from '$lib/gen'
+import type { UserWorkspace } from '$lib/stores'
+
+/**
+ * `$userWorkspaces` only lists workspaces the user is a *member* of. A superadmin can navigate into a
+ * workspace they don't belong to, which leaves fork surfaces (the base picker, the family picker)
+ * unable to resolve that workspace's family — so it appears empty. This composable fetches the
+ * visited-but-unlisted workspace's metadata as superadmin and appends it, so the family root resolves
+ * and can be forked. Its wider family (ancestors/siblings the caller can't see) stays unreachable
+ * client-side, so only the visited workspace itself is added.
+ */
+export function useForkableWorkspaces(args: {
+	workspaces: () => UserWorkspace[]
+	currentWorkspaceId: () => string | undefined
+	isSuperadmin: () => boolean
+	// Skip the lookup entirely when the fork surface isn't in play (defaults to always enabled).
+	enabled?: () => boolean
+}) {
+	const missing = resource(
+		() => {
+			const id = args.currentWorkspaceId()
+			const enabled = args.enabled?.() ?? true
+			return enabled && args.isSuperadmin() && id && !args.workspaces().some((w) => w.id === id)
+				? id
+				: undefined
+		},
+		async (ws) =>
+			ws ? await WorkspaceService.getWorkspaceAsSuperAdmin({ workspace: ws }) : undefined
+	)
+	return {
+		get current(): UserWorkspace[] {
+			const base = args.workspaces()
+			const w = missing.current
+			// Drop the fetched entry once membership catches up, so the id is never duplicated.
+			if (!w || base.some((b) => b.id === w.id)) return base
+			return [
+				...base,
+				{
+					id: w.id,
+					name: w.name,
+					username: '',
+					color: w.color ?? undefined,
+					parent_workspace_id: w.parent_workspace_id,
+					disabled: false
+				}
+			]
+		}
+	}
+}