diff --git a/apps/finicky/src/main.m b/apps/finicky/src/main.m
index 261191cf..ad00c07a 100644
--- a/apps/finicky/src/main.m
+++ b/apps/finicky/src/main.m
@@ -28,6 +28,8 @@ - (instancetype)initWithForceOpenWindow:(bool)forceOpenWindow initShow:(bool)sho
 
 // Use bool for openWindow and related logic
 - (void)applicationDidFinishLaunching:(NSNotification *)notification {
+    [self terminateOtherInstances];
+
     bool openWindow = self.forceOpenWindow;
     if (!openWindow) {
         // Even if we aren't forcing the window to open, we still want to open it if didn't receive a URL
@@ -44,6 +46,61 @@ - (void)applicationDidFinishLaunching:(NSNotification *)notification {
     QueueWindowDisplay(openWindow);
 }
 
+// Ensure only one Finicky process is running. macOS's Launch Services normally
+// routes GetURL events to an already-running instance, but that routing can fail
+// (stale LS registration after app moves/updates, different bundle paths, SSO
+// agents launching from another context) and silently spawn a second process
+// that proceeds to create its own status bar icon. Without a guard, duplicates
+// accumulate in the menu bar over time. Terminate any other instances we find
+// with the same bundle identifier so we're the single surviving process.
+- (void)terminateOtherInstances {
+    NSString *selfBundleID = [[NSBundle mainBundle] bundleIdentifier];
+    if (!selfBundleID) {
+        return;
+    }
+
+    NSArray<NSRunningApplication *> *instances = [NSRunningApplication runningApplicationsWithBundleIdentifier:selfBundleID];
+    pid_t myPID = [[NSRunningApplication currentApplication] processIdentifier];
+
+    NSMutableArray<NSRunningApplication *> *duplicates = [NSMutableArray array];
+    for (NSRunningApplication *app in instances) {
+        if ([app processIdentifier] == myPID) continue;
+        if ([app isTerminated]) continue;
+        [duplicates addObject:app];
+    }
+
+    if (duplicates.count == 0) {
+        return;
+    }
+
+    // -[NSRunningApplication terminate] returning YES only means the request was
+    // sent, not that the target has exited. Fire all requests in parallel, then
+    // share a single deadline across the poll so 16 hung duplicates don't cost
+    // 16x the wait budget.
+    for (NSRunningApplication *app in duplicates) {
+        NSLog(@"Terminating duplicate Finicky instance (pid %d)", [app processIdentifier]);
+        [app terminate];
+    }
+
+    NSDate *deadline = [NSDate dateWithTimeIntervalSinceNow:1.0];
+    while ([deadline timeIntervalSinceNow] > 0) {
+        BOOL anyAlive = NO;
+        for (NSRunningApplication *app in duplicates) {
+            if (![app isTerminated]) { anyAlive = YES; break; }
+        }
+        if (!anyAlive) return;
+
+        [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode
+                                 beforeDate:[NSDate dateWithTimeIntervalSinceNow:0.05]];
+    }
+
+    for (NSRunningApplication *app in duplicates) {
+        if ([app isTerminated]) continue;
+        NSLog(@"Duplicate Finicky instance (pid %d) did not exit within 1s; force-terminating", [app processIdentifier]);
+        [app forceTerminate];
+    }
+}
+
 - (BOOL)applicationShouldHandleReopen:(NSApplication *)sender hasVisibleWindows:(BOOL)flag {
     if (!flag) {
         // If there are no visible windows, we should open a new one