diff --git a/go/bind/notifications.go b/go/bind/notifications.go
index 3e1a9ddbbc2..4482a7ca596 100644
--- a/go/bind/notifications.go
+++ b/go/bind/notifications.go
@@ -6,8 +6,11 @@ import (
 	"fmt"
 	"regexp"
 	"runtime"
+	"strconv"
+	"sync"
 	"time"
 
+	lru "github.com/hashicorp/golang-lru"
 	"github.com/keybase/client/go/chat"
 	"github.com/keybase/client/go/chat/globals"
 	"github.com/keybase/client/go/chat/storage"
@@ -20,6 +23,21 @@ import (
 	"github.com/kyokomi/emoji"
 )
 
+const seenNotificationsCacheSize = 100
+
+var (
+	seenNotificationsMtx  sync.Mutex
+	seenNotifications     *lru.Cache
+	seenNotificationsOnce sync.Once
+)
+
+func getSeenNotificationsCache() *lru.Cache {
+	seenNotificationsOnce.Do(func() {
+		seenNotifications, _ = lru.New(seenNotificationsCacheSize)
+	})
+	return seenNotifications
+}
+
 type Person struct {
 	KeybaseUsername string
 	KeybaseAvatar   string
@@ -106,6 +124,20 @@ func HandleBackgroundNotification(strConvID, body, serverMessageBody, sender str
 		return libkb.LoginRequiredError{}
 	}
 	mp := chat.NewMobilePush(gc)
+	// Dedupe by convID||msgID
+	dupKey := strConvID + "||" + strconv.Itoa(intMessageID)
+	// Check if we've already processed this notification but without
+	// serializing the whole function. We check the map again while holding
+	// a lock before anything is displayed.
+	if _, ok := getSeenNotificationsCache().Get(dupKey); ok {
+		// Cancel any duplicate visible notifications
+		if len(pushID) > 0 {
+			mp.AckNotificationSuccess(ctx, []string{pushID})
+		}
+		kbCtx.Log.CDebugf(ctx, "HandleBackgroundNotification: duplicate notification convID=%s msgID=%d", strConvID, intMessageID)
+		// Return nil (not an error) so Android does not treat this as failure and show a fallback notification.
+		return nil
+	}
 	uid := gregor1.UID(kbCtx.Env.GetUID().ToBytes())
 	convID, err := chat1.MakeConvID(strConvID)
 	if err != nil {
@@ -195,7 +227,20 @@ func HandleBackgroundNotification(strConvID, body, serverMessageBody, sender str
 
 	// only display and ack this notification if we actually have something to display
 	if pusher != nil && (len(chatNotification.Message.Plaintext) > 0 || len(chatNotification.Message.ServerMessage) > 0) {
+		// Lock and check if we've already processed this notification.
+		seenNotificationsMtx.Lock()
+		defer seenNotificationsMtx.Unlock()
+		if _, ok := getSeenNotificationsCache().Get(dupKey); ok {
+			// Cancel any duplicate visible notifications
+			if len(pushID) > 0 {
+				mp.AckNotificationSuccess(ctx, []string{pushID})
+			}
+			kbCtx.Log.CDebugf(ctx, "HandleBackgroundNotification: duplicate notification convID=%s msgID=%d", strConvID, intMessageID)
+			// Return nil (not an error) so Android does not treat this as failure and show a fallback notification.
+			return nil
+		}
 		pusher.DisplayChatNotification(&chatNotification)
+		getSeenNotificationsCache().Add(dupKey, struct{}{})
 		if len(pushID) > 0 {
 			mp.AckNotificationSuccess(ctx, []string{pushID})
 		}