diff --git a/lib/shared/markdown.js b/lib/shared/markdown.js
--- a/lib/shared/markdown.js
+++ b/lib/shared/markdown.js
@@ -251,6 +251,47 @@
 }
 
 const spoilerRegex: RegExp = /^\|\|([^\n]+?)\|\|/g;
+const spoilerReplacement: string = '⬛⬛⬛';
+
+function traverseASTForSpoilers(ast: SingleASTNode[]): SingleASTNode[] {
+  return traverseASTRecursively(ast, false);
+}
+
+function traverseASTRecursively(
+  ast: SingleASTNode[],
+  isTextASpoiler: boolean,
+): SingleASTNode[] {
+  return ast.map(node => {
+    return {
+      ...node,
+      content: replaceSpoilers(node.type, node.content, isTextASpoiler),
+    };
+  });
+}
+
+function replaceSpoilers(
+  type: string,
+  content: string,
+  isTextASpoiler: boolean,
+): SingleASTNode[] | string {
+  // Check if content is an array - if it is, we need to continue traversing
+  if (Array.isArray(content)) {
+    const isTypeASpoiler = type === 'spoiler';
+    return traverseASTRecursively(content, isTextASpoiler || isTypeASpoiler);
+  }
+  // Text Node within a spoiler node (i.e. isTextASpoiler === true),
+  // so we replace the text with the spoiler replacement
+  if (type === 'text' && isTextASpoiler) {
+    return spoilerReplacement;
+  }
+  // Text Node outside of a spoiler node (i.e. isTextASpoiler === false),
+  // so we maintain the original text content
+  if (type === 'text') {
+    return content;
+  }
+  // All other instances of a node type
+  return content;
+}
 
 export {
   paragraphRegex,
@@ -272,4 +313,5 @@
   matchList,
   parseList,
   matchMentions,
+  traverseASTForSpoilers,
 };
diff --git a/lib/shared/messages/text-message-spec.js b/lib/shared/messages/text-message-spec.js
--- a/lib/shared/messages/text-message-spec.js
+++ b/lib/shared/messages/text-message-spec.js
@@ -16,7 +16,11 @@
 import type { NotifTexts } from '../../types/notif-types';
 import type { ThreadInfo } from '../../types/thread-types';
 import type { RelativeUserInfo } from '../../types/user-types';
-import { type ASTNode, type SingleASTNode } from '../markdown';
+import {
+  type ASTNode,
+  type SingleASTNode,
+  traverseASTForSpoilers,
+} from '../markdown';
 import { threadIsGroupChat } from '../thread-utils';
 import { stringForUser } from '../user-utils';
 import type {
@@ -85,8 +89,9 @@
   messageTitle({ messageInfo, markdownRules }) {
     const { text } = messageInfo;
     const parser = SimpleMarkdown.parserFor(markdownRules);
-    const ast = parser(text, { disableAutoBlockNewlines: true });
-
+    const ast = traverseASTForSpoilers(
+      parser(text, { disableAutoBlockNewlines: true }),
+    );
     return getFirstNonQuotedRawLine(ast).trim();
   },