diff --git a/lib/shared/reaction-utils.js b/lib/shared/reaction-utils.js
--- a/lib/shared/reaction-utils.js
+++ b/lib/shared/reaction-utils.js
@@ -33,6 +33,22 @@
   return reactionText.join(' ');
 }
 
+function getViewerAlreadySelectedMessageReactions(
+  reactions: ReactionInfo,
+): $ReadOnlyArray<string> {
+  const alreadySelectedEmojis = [];
+
+  for (const reaction in reactions) {
+    const reactionInfo = reactions[reaction];
+
+    if (reactionInfo.viewerReacted) {
+      alreadySelectedEmojis.push(reaction);
+    }
+  }
+
+  return alreadySelectedEmojis;
+}
+
 type MessageReactionListInfo = {
   +id: string,
   +isViewer: boolean,
@@ -103,6 +119,7 @@
 
 export {
   stringForReactionList,
+  getViewerAlreadySelectedMessageReactions,
   useMessageReactionsList,
   useCanCreateReactionFromMessage,
 };
diff --git a/native/chat/multimedia-message-tooltip-button.react.js b/native/chat/multimedia-message-tooltip-button.react.js
--- a/native/chat/multimedia-message-tooltip-button.react.js
+++ b/native/chat/multimedia-message-tooltip-button.react.js
@@ -4,7 +4,10 @@
 import Animated from 'react-native-reanimated';
 
 import { localIDPrefix } from 'lib/shared/message-utils.js';
-import { useCanCreateReactionFromMessage } from 'lib/shared/reaction-utils.js';
+import {
+  getViewerAlreadySelectedMessageReactions,
+  useCanCreateReactionFromMessage,
+} from 'lib/shared/reaction-utils.js';
 
 import { TooltipInlineEngagement } from './inline-engagement.react.js';
 import { InnerMultimediaMessage } from './inner-multimedia-message.react.js';
@@ -152,7 +155,10 @@
     [sendReaction, dismissTooltip],
   );
 
-  const alreadySelectedEmojis = React.useMemo(() => [], []);
+  const alreadySelectedEmojis = React.useMemo(
+    () => getViewerAlreadySelectedMessageReactions(item.reactions),
+    [item.reactions],
+  );
 
   return (
     <>
diff --git a/native/chat/robotext-message-tooltip-button.react.js b/native/chat/robotext-message-tooltip-button.react.js
--- a/native/chat/robotext-message-tooltip-button.react.js
+++ b/native/chat/robotext-message-tooltip-button.react.js
@@ -4,7 +4,10 @@
 import Animated from 'react-native-reanimated';
 
 import { localIDPrefix } from 'lib/shared/message-utils.js';
-import { useCanCreateReactionFromMessage } from 'lib/shared/reaction-utils.js';
+import {
+  getViewerAlreadySelectedMessageReactions,
+  useCanCreateReactionFromMessage,
+} from 'lib/shared/reaction-utils.js';
 
 import { TooltipInlineEngagement } from './inline-engagement.react.js';
 import { InnerRobotextMessage } from './inner-robotext-message.react.js';
@@ -135,7 +138,10 @@
     [sendReaction, dismissTooltip],
   );
 
-  const alreadySelectedEmojis = React.useMemo(() => [], []);
+  const alreadySelectedEmojis = React.useMemo(
+    () => getViewerAlreadySelectedMessageReactions(item.reactions),
+    [item.reactions],
+  );
 
   return (
     <>
diff --git a/native/chat/text-message-tooltip-button.react.js b/native/chat/text-message-tooltip-button.react.js
--- a/native/chat/text-message-tooltip-button.react.js
+++ b/native/chat/text-message-tooltip-button.react.js
@@ -4,7 +4,10 @@
 import Animated from 'react-native-reanimated';
 
 import { localIDPrefix } from 'lib/shared/message-utils.js';
-import { useCanCreateReactionFromMessage } from 'lib/shared/reaction-utils.js';
+import {
+  getViewerAlreadySelectedMessageReactions,
+  useCanCreateReactionFromMessage,
+} from 'lib/shared/reaction-utils.js';
 
 import { TooltipInlineEngagement } from './inline-engagement.react.js';
 import { InnerTextMessage } from './inner-text-message.react.js';
@@ -149,7 +152,10 @@
     [sendReaction, dismissTooltip],
   );
 
-  const alreadySelectedEmojis = React.useMemo(() => [], []);
+  const alreadySelectedEmojis = React.useMemo(
+    () => getViewerAlreadySelectedMessageReactions(item.reactions),
+    [item.reactions],
+  );
 
   return (
     <MessageListContextProvider threadInfo={threadInfo}>
diff --git a/native/components/emoji-keyboard.react.js b/native/components/emoji-keyboard.react.js
--- a/native/components/emoji-keyboard.react.js
+++ b/native/components/emoji-keyboard.react.js
@@ -76,6 +76,12 @@
     (emoji: EmojiSelection) => {
       if (!selectMultipleEmojis) {
         setCurrentlySelected([emoji.name]);
+      } else if (emoji.alreadySelected) {
+        setCurrentlySelected(prev =>
+          prev.filter(emojiName => emojiName !== emoji.name),
+        );
+      } else {
+        setCurrentlySelected(prev => [...prev, emoji.name]);
       }
       onEmojiSelected(emoji);
     },