diff --git a/web/modals/threads/sidebars/sidebar.react.js b/web/modals/threads/sidebars/sidebar.react.js
--- a/web/modals/threads/sidebars/sidebar.react.js
+++ b/web/modals/threads/sidebars/sidebar.react.js
@@ -1,5 +1,5 @@
 // @flow
-
+import classNames from 'classnames';
 import * as React from 'react';
 
 import { useModalContext } from 'lib/components/modal-provider.react';
@@ -21,6 +21,7 @@
 function Sidebar(props: Props): React.Node {
   const { sidebar, isLastItem } = props;
   const { threadInfo, lastUpdatedTime, mostRecentMessageInfo } = sidebar;
+  const { unread } = threadInfo.currentUser;
 
   const timeZone = useSelector(state => state.timeZone);
   const { popModal } = useModalContext();
@@ -40,6 +41,16 @@
     [lastUpdatedTime, timeZone],
   );
 
+  const longTextEllipsisClassName = classNames({
+    [css.longTextEllipsis]: true,
+    [css.unread]: unread,
+  });
+
+  const lastActivityClassName = classNames({
+    [css.lastActivity]: true,
+    [css.unread]: unread,
+  });
+
   const lastMessage = React.useMemo(() => {
     if (!mostRecentMessageInfo) {
       return <div className={css.noMessage}>No messages</div>;
@@ -52,11 +63,17 @@
     const previewText = username ? `${username}: ${message}` : message;
     return (
       <>
-        <div className={css.longTextEllipsis}>{previewText}</div>
-        <div className={css.lastActivity}>{lastActivity}</div>
+        <div className={longTextEllipsisClassName}>{previewText}</div>
+        <div className={lastActivityClassName}>{lastActivity}</div>
       </>
     );
-  }, [lastActivity, mostRecentMessageInfo, threadInfo]);
+  }, [
+    lastActivity,
+    lastActivityClassName,
+    longTextEllipsisClassName,
+    mostRecentMessageInfo,
+    threadInfo,
+  ]);
 
   return (
     <Button className={css.sidebarContainer} onClick={onClickThread}>
diff --git a/web/modals/threads/sidebars/sidebars-modal.css b/web/modals/threads/sidebars/sidebars-modal.css
--- a/web/modals/threads/sidebars/sidebars-modal.css
+++ b/web/modals/threads/sidebars/sidebars-modal.css
@@ -62,6 +62,11 @@
   white-space: nowrap;
 }
 
+div.unread {
+  color: var(--fg);
+  font-weight: var(--semi-bold);
+}
+
 img.sidebarArrow {
   position: relative;
   top: -12px;