diff --git a/src/lib/components/CollaboratorPopover.svelte b/src/lib/components/CollaboratorPopover.svelte
new file mode 100644
index 0000000..07ef66d
--- /dev/null
+++ b/src/lib/components/CollaboratorPopover.svelte
@@ -0,0 +1,68 @@
+<script lang="ts">
+	import type { Collaborator } from '$lib/types/index.js';
+	import Users from 'lucide-svelte/icons/users';
+
+	interface Props {
+		collaborators: Collaborator[];
+		ownerName?: string;
+	}
+
+	const { collaborators, ownerName }: Props = $props();
+
+	let showPopover = $state(false);
+	let hoverTimeout: ReturnType<typeof setTimeout> | undefined;
+
+	function handleMouseEnter() {
+		hoverTimeout = setTimeout(() => {
+			showPopover = true;
+		}, 150);
+	}
+
+	function handleMouseLeave() {
+		clearTimeout(hoverTimeout);
+		showPopover = false;
+	}
+
+	function handleClick(e: Event) {
+		e.stopPropagation();
+		showPopover = !showPopover;
+	}
+</script>
+
+<!-- svelte-ignore a11y_no_static_element_interactions -->
+<div
+	class="relative inline-flex"
+	onmouseenter={handleMouseEnter}
+	onmouseleave={handleMouseLeave}
+>
+	<button
+		type="button"
+		class="rounded-sm p-1 text-[var(--text-muted)] hover:text-[var(--primary)]"
+		title="Shared note"
+		onclick={handleClick}
+		data-testid="collaborator-indicator"
+	>
+		<Users class="h-4 w-4" />
+	</button>
+
+	{#if showPopover}
+		<div
+			class="absolute left-0 bottom-full z-20 mb-1 min-w-[160px] rounded-sm border border-[var(--border-subtle)] bg-[var(--bg-surface)] p-2 shadow-[var(--card-shadow)] animate-[fade-in_150ms_ease-out]"
+			data-testid="collaborator-popover"
+		>
+			<p class="mb-1 text-xs font-semibold text-[var(--text-muted)]">Shared with</p>
+			<ul class="space-y-0.5">
+				{#if ownerName}
+					<li class="text-xs text-[var(--text)]">
+						{ownerName} <span class="text-[var(--text-muted)]">(Owner)</span>
+					</li>
+				{/if}
+				{#each collaborators as collab}
+					<li class="text-xs text-[var(--text)]">
+						{collab.displayName || collab.email}
+					</li>
+				{/each}
+			</ul>
+		</div>
+	{/if}
+</div>
diff --git a/src/lib/components/NoteCard.svelte b/src/lib/components/NoteCard.svelte
index 3ef6527..dab4a7b 100644
--- a/src/lib/components/NoteCard.svelte
+++ b/src/lib/components/NoteCard.svelte
@@ -1,15 +1,17 @@
 <script lang="ts">
 	import { NOTE_COLORS } from '$lib/utils/colors.js';
 	import { renderMarkdown } from '$lib/utils/markdown.js';
-	import { togglePin, trashNote, archiveNote, unarchiveNote, restoreNote, deleteNote, updateNote, currentFilter } from '$lib/stores/notes.js';
+	import { togglePin, trashNote, archiveNote, unarchiveNote, restoreNote, deleteNote, updateNote, leaveNote, currentFilter } from '$lib/stores/notes.js';
 	import TagChip from './TagChip.svelte';
 	import ImageLightbox from './ImageLightbox.svelte';
+	import CollaboratorPopover from './CollaboratorPopover.svelte';
 	import type { Note } from '$lib/types/index.js';
 	import Undo2 from 'lucide-svelte/icons/undo-2';
 	import Trash2 from 'lucide-svelte/icons/trash-2';
 	import Bookmark from 'lucide-svelte/icons/bookmark';
 	import Archive from 'lucide-svelte/icons/archive';
 	import ArchiveRestore from 'lucide-svelte/icons/archive-restore';
+	import UserMinus from 'lucide-svelte/icons/user-minus';
 
 	interface ChecklistItem {
 		text: string;
@@ -112,16 +114,25 @@
 		</div>
 	{/if}
 
-	{#if note.pinned}
-		<button
-			onclick={stop(() => togglePin(note.id, note.pinned))}
-			class="absolute top-1.5 right-1.5 rounded-sm p-1 text-[var(--primary)] hover:bg-[var(--border)]/10"
-			title="Unpin"
-			data-testid="pin-indicator"
-		>
-			<Bookmark class="h-4 w-4 fill-[var(--primary)]" />
-		</button>
-	{/if}
+	<!-- Status indicators (top-right) -->
+	<div class="absolute top-1.5 right-1.5 flex items-center gap-0.5">
+		{#if note.isShared && note.collaborators}
+			<CollaboratorPopover
+				collaborators={note.collaborators}
+				ownerName={note.isOwner ? 'You' : undefined}
+			/>
+		{/if}
+		{#if note.pinned}
+			<button
+				onclick={stop(() => togglePin(note.id, note.pinned))}
+				class="rounded-sm p-1 text-[var(--primary)] hover:bg-[var(--border)]/10"
+				title="Unpin"
+				data-testid="pin-indicator"
+			>
+				<Bookmark class="h-4 w-4 fill-[var(--primary)]" />
+			</button>
+		{/if}
+	</div>
 
 	{#if note.title}
 		<h3 class="mb-2 text-sm font-semibold text-[var(--text)]">{note.title}</h3>
@@ -208,14 +219,25 @@
 					<Archive class="h-4 w-4" />
 				</button>
 			{/if}
-			<button
-				onclick={stop(() => trashNote(note.id))}
-				class="rounded-sm p-1.5 hover:bg-[var(--border)]/10"
-				title="Delete"
-				data-testid="trash-btn"
-			>
-				<Trash2 class="h-4 w-4" />
-			</button>
+			{#if note.isShared && !note.isOwner}
+				<button
+					onclick={stop(() => leaveNote(note.id))}
+					class="rounded-sm p-1.5 hover:bg-[var(--border)]/10"
+					title="Leave note"
+					data-testid="leave-btn"
+				>
+					<UserMinus class="h-4 w-4" />
+				</button>
+			{:else}
+				<button
+					onclick={stop(() => trashNote(note.id))}
+					class="rounded-sm p-1.5 hover:bg-[var(--border)]/10"
+					title="Delete"
+					data-testid="trash-btn"
+				>
+					<Trash2 class="h-4 w-4" />
+				</button>
+			{/if}
 		{/if}
 	</div>
 
diff --git a/src/lib/components/NoteEditor.svelte b/src/lib/components/NoteEditor.svelte
index 1f5db35..eece705 100644
--- a/src/lib/components/NoteEditor.svelte
+++ b/src/lib/components/NoteEditor.svelte
@@ -4,16 +4,20 @@
 	import FormattingToolbar from './FormattingToolbar.svelte';
 	import TiptapEditor from './TiptapEditor.svelte';
 	import ImageUpload from './ImageUpload.svelte';
+	import ShareDialog from './ShareDialog.svelte';
 	import { updateNote, createNote } from '$lib/stores/notes.js';
+	import { notes } from '$lib/stores/notes.js';
 	import { NOTE_COLORS } from '$lib/utils/colors.js';
 	import type { Editor } from '@tiptap/core';
-	import type { Note, NoteColor, Attachment } from '$lib/types/index.js';
+	import type { Note, NoteColor, Attachment, Collaborator } from '$lib/types/index.js';
 	import Palette from 'lucide-svelte/icons/palette';
 	import SquareCheck from 'lucide-svelte/icons/square-check';
 	import ImageIcon from 'lucide-svelte/icons/image';
 	import Type from 'lucide-svelte/icons/type';
 	import FileCode from 'lucide-svelte/icons/file-code';
 	import FileText from 'lucide-svelte/icons/file-text';
+	import UserPlus from 'lucide-svelte/icons/user-plus';
+	import Users from 'lucide-svelte/icons/users';
 
 	interface Props {
 		note: Note | null;
@@ -48,6 +52,36 @@
 	// svelte-ignore state_referenced_locally
 	let attachmentsList = $state<Attachment[]>(note?.attachments ?? []);
 
+	let showShareDialog = $state(false);
+	// svelte-ignore state_referenced_locally
+	let collaboratorsList = $state<Collaborator[]>(note?.collaborators ?? []);
+	const isOwner = $derived(note?.isOwner !== false);
+	const isShared = $derived(collaboratorsList.length > 0);
+	// Use displayName from first user or 'You' for owner
+	const ownerName = $derived(isOwner ? 'You' : 'Owner');
+
+	function handleCollaboratorsUpdate(updated: Collaborator[]) {
+		collaboratorsList = updated;
+		// Update the note in the store
+		if (noteId) {
+			notes.update((list) =>
+				list.map((n) =>
+					n.id === noteId
+						? { ...n, collaborators: updated, isShared: updated.length > 0 }
+						: n
+				)
+			);
+		}
+	}
+
+	async function toggleShareDialog() {
+		if (currentlyNew) {
+			const id = await autoSave();
+			if (!id) return;
+		}
+		showShareDialog = !showShareDialog;
+	}
+
 	// Fetch attachments for existing notes if not pre-populated (e.g. loaded from IDB)
 	$effect(() => {
 		if (noteId && !currentlyNew && (!note?.attachments || note.attachments.length === 0)) {
@@ -285,6 +319,26 @@
 						<FileCode class="h-5 w-5" />
 					{/if}
 				</button>
+
+				<!-- Share button (owner only for new shares, all for viewing) -->
+				{#if isOwner}
+					<button
+						onclick={toggleShareDialog}
+						class="rounded-sm p-2 hover:bg-[var(--border)]/10"
+						title="Share note"
+						data-testid="share-toggle"
+					>
+						{#if isShared}
+							<Users class="h-5 w-5 text-[var(--primary)]" />
+						{:else}
+							<UserPlus class="h-5 w-5" />
+						{/if}
+					</button>
+				{:else if isShared}
+					<span class="flex items-center gap-1 rounded-sm p-2 text-[var(--text-muted)]" title="Shared note">
+						<Users class="h-5 w-5" />
+					</span>
+				{/if}
 			</div>
 
 			<button
@@ -297,3 +351,13 @@
 		</div>
 	</div>
 </div>
+
+{#if showShareDialog && noteId}
+	<ShareDialog
+		noteId={noteId}
+		collaborators={collaboratorsList}
+		{ownerName}
+		onClose={() => (showShareDialog = false)}
+		onUpdate={handleCollaboratorsUpdate}
+	/>
+{/if}
diff --git a/src/lib/components/ShareDialog.svelte b/src/lib/components/ShareDialog.svelte
new file mode 100644
index 0000000..d45a0cd
--- /dev/null
+++ b/src/lib/components/ShareDialog.svelte
@@ -0,0 +1,191 @@
+<script lang="ts">
+	import type { Collaborator } from '$lib/types/index.js';
+	import X from 'lucide-svelte/icons/x';
+	import UserMinus from 'lucide-svelte/icons/user-minus';
+	import Search from 'lucide-svelte/icons/search';
+	import { showToast } from '$lib/stores/toast.js';
+
+	interface UserResult {
+		id: number;
+		displayName: string;
+		email: string;
+	}
+
+	interface Props {
+		noteId: string;
+		collaborators: Collaborator[];
+		ownerName: string;
+		onClose: () => void;
+		onUpdate: (collaborators: Collaborator[]) => void;
+	}
+
+	const { noteId, collaborators, ownerName, onClose, onUpdate }: Props = $props();
+
+	let searchQuery = $state('');
+	let searchResults = $state<UserResult[]>([]);
+	let isSearching = $state(false);
+	let searchTimeout: ReturnType<typeof setTimeout> | undefined;
+
+	function handleSearch(query: string) {
+		clearTimeout(searchTimeout);
+		if (!query.trim()) {
+			searchResults = [];
+			return;
+		}
+		searchTimeout = setTimeout(async () => {
+			isSearching = true;
+			try {
+				const res = await fetch(`/api/users/search?q=${encodeURIComponent(query)}`);
+				if (res.ok) {
+					const users: UserResult[] = await res.json();
+					// Filter out existing collaborators
+					const collabIds = new Set(collaborators.map((c) => c.userId));
+					searchResults = users.filter((u) => !collabIds.has(u.id));
+				}
+			} catch {
+				// Search failed silently
+			} finally {
+				isSearching = false;
+			}
+		}, 300);
+	}
+
+	$effect(() => {
+		handleSearch(searchQuery);
+	});
+
+	async function addCollaborator(user: UserResult) {
+		try {
+			const res = await fetch(`/api/notes/${noteId}/collaborators`, {
+				method: 'POST',
+				headers: { 'Content-Type': 'application/json' },
+				body: JSON.stringify({ userId: user.id })
+			});
+			if (res.ok) {
+				const updated: Collaborator[] = await res.json();
+				onUpdate(updated);
+				searchQuery = '';
+				searchResults = [];
+				showToast(`Shared with ${user.displayName || user.email}`, 'success');
+			} else {
+				const err = await res.json().catch(() => ({ message: 'Failed to share' }));
+				showToast(err.message || 'Failed to share', 'error');
+			}
+		} catch {
+			showToast('Failed to share note', 'error');
+		}
+	}
+
+	async function removeCollaborator(userId: number) {
+		try {
+			const res = await fetch(`/api/notes/${noteId}/collaborators?userId=${userId}`, {
+				method: 'DELETE'
+			});
+			if (res.ok) {
+				const updated = collaborators.filter((c) => c.userId !== userId);
+				onUpdate(updated);
+			}
+		} catch {
+			showToast('Failed to remove collaborator', 'error');
+		}
+	}
+
+	function handleKeydown(e: KeyboardEvent) {
+		if (e.key === 'Escape') {
+			onClose();
+		}
+	}
+</script>
+
+<!-- svelte-ignore a11y_no_static_element_interactions -->
+<div
+	class="fixed inset-0 z-50 flex items-start justify-center overflow-y-auto bg-black/50 pt-20 pb-10 animate-[fade-in_150ms_ease-out]"
+	onclick={onClose}
+	onkeydown={handleKeydown}
+	data-testid="share-dialog-overlay"
+>
+	<!-- svelte-ignore a11y_no_static_element_interactions -->
+	<div
+		class="mx-4 w-full max-w-sm rounded-sm border border-[var(--border)] bg-[var(--bg-surface)] shadow-[var(--card-shadow)] animate-[pop-in_150ms_ease-out]"
+		onclick={(e) => e.stopPropagation()}
+		onkeydown={(e) => e.stopPropagation()}
+		data-testid="share-dialog"
+	>
+		<!-- Header -->
+		<div class="flex items-center justify-between border-b border-[var(--border-subtle)] px-4 py-3">
+			<h2 class="text-sm font-semibold text-[var(--text)]">Share note</h2>
+			<button
+				onclick={onClose}
+				class="rounded-sm p-1 hover:bg-[var(--border)]/10"
+				title="Close"
+			>
+				<X class="h-4 w-4" />
+			</button>
+		</div>
+
+		<!-- Search input -->
+		<div class="relative px-4 pt-3">
+			<div class="relative">
+				<Search class="absolute left-2 top-1/2 h-4 w-4 -translate-y-1/2 text-[var(--text-muted)]" />
+				<input
+					type="text"
+					placeholder="Search users..."
+					bind:value={searchQuery}
+					class="w-full rounded-sm border border-[var(--border-subtle)] bg-[var(--bg-base)] py-2 pl-8 pr-3 text-sm text-[var(--text)] outline-none placeholder:text-[var(--text-muted)] focus:border-[var(--primary)]"
+					data-testid="share-search-input"
+				/>
+			</div>
+
+			<!-- Search results dropdown -->
+			{#if searchResults.length > 0}
+				<ul class="absolute left-4 right-4 z-10 mt-1 max-h-40 overflow-y-auto rounded-sm border border-[var(--border-subtle)] bg-[var(--bg-surface)] shadow-[var(--card-shadow)]" data-testid="share-search-results">
+					{#each searchResults as user}
+						<li>
+							<button
+								type="button"
+								class="w-full px-3 py-2 text-left text-sm text-[var(--text)] hover:bg-[var(--primary)]/10"
+								onclick={() => addCollaborator(user)}
+								data-testid="share-user-result"
+							>
+								<span class="font-medium">{user.displayName || 'User'}</span>
+								{#if user.email}
+									<span class="ml-1 text-[var(--text-muted)]">{user.email}</span>
+								{/if}
+							</button>
+						</li>
+					{/each}
+				</ul>
+			{/if}
+		</div>
+
+		<!-- Current collaborators -->
+		<div class="px-4 py-3">
+			<p class="mb-2 text-xs font-semibold text-[var(--text-muted)]">People with access</p>
+			<ul class="space-y-1">
+				<!-- Owner -->
+				<li class="flex items-center justify-between rounded-sm px-2 py-1.5">
+					<span class="text-sm text-[var(--text)]">
+						{ownerName}
+						<span class="text-xs text-[var(--text-muted)]">(Owner)</span>
+					</span>
+				</li>
+				<!-- Collaborators -->
+				{#each collaborators as collab}
+					<li class="flex items-center justify-between rounded-sm px-2 py-1.5 hover:bg-[var(--border)]/10" data-testid="share-collaborator">
+						<span class="text-sm text-[var(--text)]">
+							{collab.displayName || collab.email}
+						</span>
+						<button
+							onclick={() => removeCollaborator(collab.userId)}
+							class="rounded-sm p-1 text-[var(--text-muted)] hover:text-[var(--destructive)]"
+							title="Remove"
+							data-testid="remove-collaborator-btn"
+						>
+							<UserMinus class="h-4 w-4" />
+						</button>
+					</li>
+				{/each}
+			</ul>
+		</div>
+	</div>
+</div>