diff --git a/ui/colony/src/App.tsx b/ui/colony/src/App.tsx
index b2b3214..25b6c7e 100644
--- a/ui/colony/src/App.tsx
+++ b/ui/colony/src/App.tsx
@@ -108,11 +108,21 @@ export default function App() {
   const messagesById = new Map(messages.map((m) => [m.id, m]));
   const activeChannel = channels.find((c) => c.id === activeChannelId);
 
+  // Sort channels by last opened (stored in localStorage)
+  function getLastOpened(channelId: string): number {
+    return Number(localStorage.getItem(`colony_last_opened_${channelId}`)) || 0;
+  }
+  function markOpened(channelId: string) {
+    localStorage.setItem(`colony_last_opened_${channelId}`, String(Date.now()));
+  }
+  const sortedChannels = [...channels].sort((a, b) => getLastOpened(b.id) - getLastOpened(a.id));
+
   const sidebar = (
     <ChannelSidebar
-      channels={channels}
+      channels={sortedChannels}
       activeId={activeChannelId}
       onSelect={(id) => {
+        markOpened(id);
         setActiveChannelId(id);
         setSheetOpen(false);
       }}