diff --git a/web/CommIcon.react.js b/web/CommIcon.react.js
--- a/web/CommIcon.react.js
+++ b/web/CommIcon.react.js
@@ -17,7 +17,8 @@
   | 'copy-filled'
   | 'emote-smile-filled'
   | 'pin'
-  | 'unpin';
+  | 'unpin'
+  | 'pin-mirror';
 
 type CommIconProps = {
   +icon: CommIcons,
diff --git a/web/chat/chat-message-list.css b/web/chat/chat-message-list.css
--- a/web/chat/chat-message-list.css
+++ b/web/chat/chat-message-list.css
@@ -236,3 +236,16 @@
 div.avatarOffset {
   width: 40px;
 }
+
+.pinIconContainer {
+  position: absolute;
+  top: 1px;
+}
+
+.pinIconLeft {
+  left: -20px;
+}
+
+.pinIconRight {
+  right: -20px;
+}
diff --git a/web/chat/chat-message-list.react.js b/web/chat/chat-message-list.react.js
--- a/web/chat/chat-message-list.react.js
+++ b/web/chat/chat-message-list.react.js
@@ -178,6 +178,7 @@
       <Message
         item={item}
         threadInfo={threadInfo}
+        shouldDisplayPinIndicator={true}
         key={ChatMessageList.keyExtractor(item)}
       />
     );
diff --git a/web/chat/composed-message.react.js b/web/chat/composed-message.react.js
--- a/web/chat/composed-message.react.js
+++ b/web/chat/composed-message.react.js
@@ -17,6 +17,7 @@
 import css from './chat-message-list.css';
 import FailedSend from './failed-send.react.js';
 import InlineEngagement from './inline-engagement.react.js';
+import CommIcon from '../CommIcon.react.js';
 import UserAvatar from '../components/user-avatar.react.js';
 import { type InputState, InputStateContext } from '../input/input-state.js';
 import { shouldRenderAvatars } from '../utils/avatar-utils.js';
@@ -47,6 +48,7 @@
 type BaseProps = {
   +item: ChatMessageInfoItem,
   +threadInfo: ThreadInfo,
+  +shouldDisplayPinIndicator: boolean,
   +sendFailed: boolean,
   +children: React.Node,
   +fixedWidth?: boolean,
@@ -69,8 +71,9 @@
 
   render(): React.Node {
     assertComposableMessageType(this.props.item.messageInfo.type);
-    const { borderRadius, item, threadInfo } = this.props;
-    const { hasBeenEdited } = item;
+    const { borderRadius, item, threadInfo, shouldDisplayPinIndicator } =
+      this.props;
+    const { hasBeenEdited, isPinned } = item;
     const { id, creator } = item.messageInfo;
     const threadColor = threadInfo.color;
 
@@ -163,6 +166,25 @@
       avatar = <div className={css.avatarOffset} />;
     }
 
+    const pinIconPositioning = isViewer ? 'left' : 'right';
+    const pinIconName = pinIconPositioning === 'left' ? 'pin-mirror' : 'pin';
+    const pinIconContainerClassName = classNames({
+      [css.pinIconContainer]: true,
+      [css.pinIconLeft]: pinIconPositioning === 'left',
+      [css.pinIconRight]: pinIconPositioning === 'right',
+    });
+    let pinIcon;
+    if (isPinned && shouldDisplayPinIndicator) {
+      pinIcon = (
+        <div
+          className={pinIconContainerClassName}
+          style={{ color: `#${threadColor}` }}
+        >
+          <CommIcon icon={pinIconName} size={12} />
+        </div>
+      );
+    }
+
     return (
       <React.Fragment>
         {authorName}
@@ -173,6 +195,7 @@
             onMouseEnter={this.props.onMouseEnter}
             onMouseLeave={this.props.onMouseLeave}
           >
+            {pinIcon}
             <div className={messageBoxClassName} style={messageBoxStyle}>
               {this.props.children}
             </div>
diff --git a/web/chat/message.react.js b/web/chat/message.react.js
--- a/web/chat/message.react.js
+++ b/web/chat/message.react.js
@@ -16,6 +16,7 @@
 type Props = {
   +item: ChatMessageInfoItem,
   +threadInfo: ThreadInfo,
+  +shouldDisplayPinIndicator: boolean,
 };
 function Message(props: Props): React.Node {
   const { item } = props;
@@ -30,12 +31,24 @@
   }
   let message;
   if (item.messageInfo.type === messageTypes.TEXT) {
-    message = <TextMessage item={item} threadInfo={props.threadInfo} />;
+    message = (
+      <TextMessage
+        item={item}
+        threadInfo={props.threadInfo}
+        shouldDisplayPinIndicator={props.shouldDisplayPinIndicator}
+      />
+    );
   } else if (
     item.messageInfo.type === messageTypes.IMAGES ||
     item.messageInfo.type === messageTypes.MULTIMEDIA
   ) {
-    message = <MultimediaMessage item={item} threadInfo={props.threadInfo} />;
+    message = (
+      <MultimediaMessage
+        item={item}
+        threadInfo={props.threadInfo}
+        shouldDisplayPinIndicator={props.shouldDisplayPinIndicator}
+      />
+    );
   } else {
     invariant(item.robotext, "Flow can't handle our fancy types :(");
     message = <RobotextMessage item={item} threadInfo={props.threadInfo} />;
diff --git a/web/chat/multimedia-message.react.js b/web/chat/multimedia-message.react.js
--- a/web/chat/multimedia-message.react.js
+++ b/web/chat/multimedia-message.react.js
@@ -15,6 +15,7 @@
 type BaseProps = {
   +item: ChatMessageInfoItem,
   +threadInfo: ThreadInfo,
+  +shouldDisplayPinIndicator: boolean,
 };
 type Props = {
   ...BaseProps,
@@ -75,6 +76,7 @@
       <ComposedMessage
         item={item}
         threadInfo={this.props.threadInfo}
+        shouldDisplayPinIndicator={this.props.shouldDisplayPinIndicator}
         sendFailed={sendFailed(item, inputState)}
         fixedWidth={multimedia.length > 1}
         borderRadius={16}
diff --git a/web/chat/text-message.react.js b/web/chat/text-message.react.js
--- a/web/chat/text-message.react.js
+++ b/web/chat/text-message.react.js
@@ -19,6 +19,7 @@
 type Props = {
   +item: ChatMessageInfoItem,
   +threadInfo: ThreadInfo,
+  +shouldDisplayPinIndicator: boolean,
 };
 function TextMessage(props: Props): React.Node {
   invariant(
@@ -55,6 +56,7 @@
     <ComposedMessage
       item={props.item}
       threadInfo={props.threadInfo}
+      shouldDisplayPinIndicator={props.shouldDisplayPinIndicator}
       sendFailed={textMessageSendFailed(props.item)}
     >
       <div className={messageClassName} style={messageStyle}>
diff --git a/web/components/message-result.react.js b/web/components/message-result.react.js
--- a/web/components/message-result.react.js
+++ b/web/components/message-result.react.js
@@ -42,6 +42,7 @@
             <Message
               item={item}
               threadInfo={threadInfo}
+              shouldDisplayPinIndicator={false}
               key={item.messageInfo.id}
             />
           </MessageListContext.Provider>