diff --git a/src/components/AdminShell.tsx b/src/components/AdminShell.tsx
index 470f346..bb27423 100644
--- a/src/components/AdminShell.tsx
+++ b/src/components/AdminShell.tsx
@@ -14,6 +14,7 @@ import AdminSidebar from "./AdminSidebar";
 import { isExternalIdentity } from "~/lib/admin-auth";
 import { clearAdminSession, hasAdminSession, setAdminSession } from "~/lib/admin-session";
 import { normalizeAllowedModules } from "~/lib/admin/module-access";
+import { sessionExpired, clearSessionExpired, installSessionExpiryWatcher } from "~/lib/session-expired";
 
 type Tab = { href: string; label: string; exact?: boolean };
 type SearchResult = { id: string; title: string; subtitle: string; href: string };
@@ -476,7 +477,21 @@ export default function AdminShell(props: { children: JSX.Element }) {
     }
   });
 
+  const goToLoginAfterExpiry = () => {
+    clearSessionExpired();
+    if (typeof sessionStorage !== "undefined") {
+      sessionStorage.removeItem("nxtgauge_admin_access_token");
+      sessionStorage.removeItem("nxtgauge_admin_preview");
+    }
+    clearAdminSession();
+    navigate(`/login?from=${encodeURIComponent(location.pathname + location.search)}`, {
+      replace: true,
+    });
+  };
+
   onMount(() => {
+    installSessionExpiryWatcher();
+
     const savedTheme = (
       typeof localStorage !== "undefined" ? localStorage.getItem("nxtgauge_admin_theme") : null
     ) as "light" | "dark" | null;
@@ -667,6 +682,41 @@ export default function AdminShell(props: { children: JSX.Element }) {
         color: isDark() ? "#E5E7EB" : "#0D0D2A",
       }}
     >
+      <Show when={sessionExpired()}>
+        <div
+          style="position:fixed;inset:0;z-index:100;display:flex;align-items:center;justify-content:center;background:rgba(13,13,42,0.55);padding:16px"
+          role="alertdialog"
+          aria-modal="true"
+          aria-labelledby="session-expired-title"
+        >
+          <div
+            style={{
+              background: isDark() ? "#111827" : "white",
+              color: isDark() ? "#E5E7EB" : "#0D0D2A",
+              "border-radius": "12px",
+              padding: "24px",
+              "max-width": "380px",
+              width: "100%",
+              "box-shadow": "0 20px 40px rgba(0,0,0,0.25)",
+            }}
+          >
+            <h2 id="session-expired-title" style="font-size:16px;font-weight:700;margin:0 0 8px">
+              You have been logged out
+            </h2>
+            <p style="font-size:14px;color:#6B7280;margin:0 0 20px">
+              Your session has expired for security reasons. Please log in again to continue.
+            </p>
+            <button
+              type="button"
+              onClick={goToLoginAfterExpiry}
+              style="width:100%;padding:10px 16px;border-radius:8px;border:none;background:#FF5E13;color:white;font-size:14px;font-weight:600;cursor:pointer"
+            >
+              Log In Again
+            </button>
+          </div>
+        </div>
+      </Show>
+
       <Show
         when={checkedSession()}
         fallback={
diff --git a/src/lib/session-expired.ts b/src/lib/session-expired.ts
new file mode 100644
index 0000000..c50862b
--- /dev/null
+++ b/src/lib/session-expired.ts
@@ -0,0 +1,42 @@
+import { createSignal } from 'solid-js';
+
+// Shared across the admin app: set to true the moment any authenticated request
+// comes back 401, so a single dialog (mounted in AdminShell) can tell the admin
+// their session expired instead of pages failing silently one by one.
+const [sessionExpired, setSessionExpired] = createSignal(false);
+
+export { sessionExpired };
+
+export function markSessionExpired(): void {
+  setSessionExpired(true);
+}
+
+export function clearSessionExpired(): void {
+  setSessionExpired(false);
+}
+
+let patched = false;
+
+/**
+ * Wrap window.fetch once so any authenticated admin request that comes back 401
+ * flips the shared session-expired signal, regardless of which page/helper made
+ * the call. Idempotent — safe to call from every AdminShell mount.
+ */
+export function installSessionExpiryWatcher(): void {
+  if (patched || typeof window === 'undefined') return;
+  patched = true;
+
+  const originalFetch = window.fetch.bind(window);
+  window.fetch = async (...args: Parameters<typeof fetch>) => {
+    const response = await originalFetch(...args);
+    if (response.status === 401) {
+      const hadToken =
+        typeof sessionStorage !== 'undefined' &&
+        Boolean(sessionStorage.getItem('nxtgauge_admin_access_token'));
+      // Only treat this as a session expiry if we were actually holding a token —
+      // otherwise this is just a normal pre-login 401 (e.g. a failed login attempt).
+      if (hadToken) markSessionExpired();
+    }
+    return response;
+  };
+}