diff --git a/src/components/application/app-navigation/base-components/nav-account-card.tsx b/src/components/application/app-navigation/base-components/nav-account-card.tsx
index 8946da8..8da9970 100644
--- a/src/components/application/app-navigation/base-components/nav-account-card.tsx
+++ b/src/components/application/app-navigation/base-components/nav-account-card.tsx
@@ -44,8 +44,9 @@ const placeholderAccounts: NavAccountType[] = [
 export const NavAccountMenu = ({
     className,
     selectedAccountId = "olivia",
+    onSignOut,
     ...dialogProps
-}: AriaDialogProps & { className?: string; accounts?: NavAccountType[]; selectedAccountId?: string }) => {
+}: AriaDialogProps & { className?: string; accounts?: NavAccountType[]; selectedAccountId?: string; onSignOut?: () => void }) => {
     const focusManager = useFocusManager();
     const dialogRef = useRef<HTMLDivElement>(null);
 
@@ -115,7 +116,7 @@ export const NavAccountMenu = ({
             </div>
 
             <div className="pt-1 pb-1.5">
-                <NavAccountCardMenuItem label="Sign out" icon={LogOut01} shortcut="⌥⇧Q" />
+                <NavAccountCardMenuItem label="Sign out" icon={LogOut01} shortcut="⌥⇧Q" onClick={onSignOut} />
             </div>
         </AriaDialog>
     );
@@ -156,10 +157,12 @@ export const NavAccountCard = ({
     popoverPlacement,
     selectedAccountId = "olivia",
     items = placeholderAccounts,
+    onSignOut,
 }: {
     popoverPlacement?: Placement;
     selectedAccountId?: string;
     items?: NavAccountType[];
+    onSignOut?: () => void;
 }) => {
     const triggerRef = useRef<HTMLDivElement>(null);
     const isDesktop = useBreakpoint("lg");
@@ -200,7 +203,7 @@ export const NavAccountCard = ({
                             )
                         }
                     >
-                        <NavAccountMenu selectedAccountId={selectedAccountId} accounts={items} />
+                        <NavAccountMenu selectedAccountId={selectedAccountId} accounts={items} onSignOut={onSignOut} />
                     </AriaPopover>
                 </AriaDialogTrigger>
             </div>
diff --git a/src/components/layout/auth-guard.tsx b/src/components/layout/auth-guard.tsx
new file mode 100644
index 0000000..7fc8acd
--- /dev/null
+++ b/src/components/layout/auth-guard.tsx
@@ -0,0 +1,12 @@
+import { Navigate, Outlet } from 'react-router';
+import { useAuth } from '@/providers/auth-provider';
+
+export const AuthGuard = () => {
+    const { isAuthenticated } = useAuth();
+
+    if (!isAuthenticated) {
+        return <Navigate to="/login" replace />;
+    }
+
+    return <Outlet />;
+};
diff --git a/src/components/layout/sidebar.tsx b/src/components/layout/sidebar.tsx
index a8cd367..177a5ff 100644
--- a/src/components/layout/sidebar.tsx
+++ b/src/components/layout/sidebar.tsx
@@ -8,13 +8,12 @@ import {
     faGrid2,
     faPlug,
 } from "@fortawesome/pro-regular-svg-icons";
+import { useNavigate } from "react-router";
 import { MobileNavigationHeader } from "@/components/application/app-navigation/base-components/mobile-header";
 import { NavAccountCard } from "@/components/application/app-navigation/base-components/nav-account-card";
 import { NavItemBase } from "@/components/application/app-navigation/base-components/nav-item";
 import type { NavItemType } from "@/components/application/app-navigation/config";
-
-// TODO: Wire to useAuth() once auth-provider.tsx is implemented
-const isAdmin = false;
+import { useAuth } from "@/providers/auth-provider";
 
 const MAIN_SIDEBAR_WIDTH = 292;
 
@@ -58,10 +57,18 @@ interface SidebarProps {
 }
 
 export const Sidebar = ({ activeUrl = "/" }: SidebarProps) => {
+    const { logout, isAdmin: authIsAdmin, user } = useAuth();
+    const navigate = useNavigate();
+
+    const handleSignOut = () => {
+        logout();
+        navigate('/login');
+    };
+
     const navSections = [
         { label: "Main", items: mainItems },
         { label: "Insights", items: insightsItems },
-        ...(isAdmin ? [{ label: "Admin", items: adminItems }] : []),
+        ...(authIsAdmin ? [{ label: "Admin", items: adminItems }] : []),
     ];
 
     const content = (
@@ -103,7 +110,7 @@ export const Sidebar = ({ activeUrl = "/" }: SidebarProps) => {
 
             {/* Account card */}
             <div className="mt-auto flex flex-col gap-5 px-2 py-4 lg:gap-6 lg:px-4 lg:py-4">
-                <NavAccountCard />
+                <NavAccountCard onSignOut={handleSignOut} />
             </div>
         </aside>
     );
diff --git a/src/main.tsx b/src/main.tsx
index 5642ba0..39a1802 100644
--- a/src/main.tsx
+++ b/src/main.tsx
@@ -2,6 +2,7 @@ import { StrictMode } from "react";
 import { createRoot } from "react-dom/client";
 import { BrowserRouter, Outlet, Route, Routes } from "react-router";
 import { AppShell } from "@/components/layout/app-shell";
+import { AuthGuard } from "@/components/layout/auth-guard";
 import { NotFound } from "@/pages/not-found";
 import { AllLeadsPage } from "@/pages/all-leads";
 import { CampaignDetailPage } from "@/pages/campaign-detail";
@@ -24,19 +25,21 @@ createRoot(document.getElementById("root")!).render(
                         <RouteProvider>
                     <Routes>
                         <Route path="/login" element={<LoginPage />} />
-                        <Route
-                            element={
-                                <AppShell>
-                                    <Outlet />
-                                </AppShell>
-                            }
-                        >
-                            <Route path="/" element={<LeadWorkspacePage />} />
-                            <Route path="/leads" element={<AllLeadsPage />} />
-                            <Route path="/campaigns" element={<CampaignsPage />} />
-                            <Route path="/campaigns/:id" element={<CampaignDetailPage />} />
-                            <Route path="/outreach" element={<OutreachPage />} />
-                            <Route path="*" element={<NotFound />} />
+                        <Route element={<AuthGuard />}>
+                            <Route
+                                element={
+                                    <AppShell>
+                                        <Outlet />
+                                    </AppShell>
+                                }
+                            >
+                                <Route path="/" element={<LeadWorkspacePage />} />
+                                <Route path="/leads" element={<AllLeadsPage />} />
+                                <Route path="/campaigns" element={<CampaignsPage />} />
+                                <Route path="/campaigns/:id" element={<CampaignDetailPage />} />
+                                <Route path="/outreach" element={<OutreachPage />} />
+                                <Route path="*" element={<NotFound />} />
+                            </Route>
                         </Route>
                     </Routes>
                         </RouteProvider>