diff --git a/package-lock.json b/package-lock.json
index 55003d64..2565ff21 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -20,8 +20,9 @@
         "@tauri-apps/plugin-dialog": "^2.6.0",
         "@tauri-apps/plugin-opener": "^2",
         "@tauri-apps/plugin-updater": "^2.10.0",
-        "@tiptap/core": "^3.19.0",
+        "@tiptap/core": "3.20.0",
         "@tiptap/extension-code-block-lowlight": "^3.20.0",
+        "@tiptap/extension-highlight": "3.20.0",
         "@tiptap/extension-image": "^3.18.0",
         "@tiptap/extension-link": "^3.18.0",
         "@tiptap/extension-mathematics": "^3.18.0",
@@ -33,7 +34,7 @@
         "@tiptap/extension-task-item": "^3.18.0",
         "@tiptap/extension-task-list": "^3.18.0",
         "@tiptap/markdown": "^3.18.0",
-        "@tiptap/pm": "^3.18.0",
+        "@tiptap/pm": "3.20.0",
         "@tiptap/react": "^3.18.0",
         "@tiptap/starter-kit": "^3.18.0",
         "@tiptap/suggestion": "^3.18.0",
@@ -2787,6 +2788,19 @@
         "@tiptap/core": "^3.20.0"
       }
     },
+    "node_modules/@tiptap/extension-highlight": {
+      "version": "3.20.0",
+      "resolved": "https://registry.npmjs.org/@tiptap/extension-highlight/-/extension-highlight-3.20.0.tgz",
+      "integrity": "sha512-ANL1wFz0s1ScNR4uBfO0s6Sz+qqGp2u6ynrCVk6TCT3d10CQ+gD1gSDTrVRC3CtlMKtHHH4fYrFAq284+J0gKA==",
+      "license": "MIT",
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/ueberdosis"
+      },
+      "peerDependencies": {
+        "@tiptap/core": "^3.20.0"
+      }
+    },
     "node_modules/@tiptap/extension-horizontal-rule": {
       "version": "3.20.0",
       "resolved": "https://registry.npmjs.org/@tiptap/extension-horizontal-rule/-/extension-horizontal-rule-3.20.0.tgz",
diff --git a/package.json b/package.json
index fb889190..430b54d7 100644
--- a/package.json
+++ b/package.json
@@ -24,6 +24,7 @@
     "@tauri-apps/plugin-updater": "^2.10.0",
     "@tiptap/core": "^3.19.0",
     "@tiptap/extension-code-block-lowlight": "^3.20.0",
+    "@tiptap/extension-highlight": "^3.20.0",
     "@tiptap/extension-image": "^3.18.0",
     "@tiptap/extension-link": "^3.18.0",
     "@tiptap/extension-mathematics": "^3.18.0",
diff --git a/src/App.css b/src/App.css
index d094bedf..17f9bc3d 100644
--- a/src/App.css
+++ b/src/App.css
@@ -16,6 +16,7 @@
   --color-border: rgba(28, 25, 23, 0.08);
   --color-accent: #1c1917;
   --color-selection: rgba(250, 204, 21, 0.4); /* Tailwind yellow-400 */
+  --color-text-selection: rgba(96, 165, 250, 0.35); /* Tailwind blue-400 */
 
   /* Editor font settings - simplified (overridden by ThemeContext) */
   --editor-font-family:
@@ -61,6 +62,7 @@
   --color-border: rgba(250, 249, 249, 0.07);
   --color-accent: #fafaf9;
   --color-selection: rgba(253, 224, 71, 0.35); /* Tailwind yellow-300 */
+  --color-text-selection: rgba(147, 197, 253, 0.3); /* Tailwind blue-300 */
 
   /* Syntax highlighting colors - Dark (GitHub) */
   --color-syntax-keyword: #ea4a5a;
@@ -145,13 +147,13 @@ body {
   -moz-osx-font-smoothing: grayscale;
 }
 
-/* Text and image selection highlight */
+/* Text and image selection highlight - always blue, distinct from yellow highlight marks */
 ::selection {
-  background-color: var(--color-selection);
+  background-color: var(--color-text-selection);
 }
 
 ::-moz-selection {
-  background-color: var(--color-selection);
+  background-color: var(--color-text-selection);
 }
 
 /* Hide scrollbar while allowing scroll */
@@ -394,6 +396,13 @@ html.dark {
   color: var(--color-text);
 }
 
+/* Highlighted text - yellow background, theme-aware text color */
+.prose mark {
+  background-color: rgba(250, 204, 21, 0.4);
+  color: inherit;
+  border-radius: 0.15em;
+}
+
 /* Code blocks and inline code */
 .prose :where(code):not(:where([class~="not-prose"], [class~="not-prose"] *)) {
   color: var(--color-code);
diff --git a/src/components/editor/Editor.tsx b/src/components/editor/Editor.tsx
index 32a8159c..677ee531 100644
--- a/src/components/editor/Editor.tsx
+++ b/src/components/editor/Editor.tsx
@@ -19,6 +19,7 @@ import Image from "@tiptap/extension-image";
 import TaskList from "@tiptap/extension-task-list";
 import TaskItem from "@tiptap/extension-task-item";
 import { TableKit } from "@tiptap/extension-table";
+import Highlight from "@tiptap/extension-highlight";
 import { Markdown } from "@tiptap/markdown";
 import CodeBlockLowlight from "@tiptap/extension-code-block-lowlight";
 import { lowlight } from "./lowlight";
@@ -79,6 +80,7 @@ import {
   BoldIcon,
   ItalicIcon,
   StrikethroughIcon,
+  HighlighterIcon,
   Heading1Icon,
   Heading2Icon,
   Heading3Icon,
@@ -283,6 +285,13 @@ function FormatBar({
       >
         <StrikethroughIcon className="w-4.5 h-4.5 stroke-[1.5]" />
       </ToolbarButton>
+      <ToolbarButton
+        onClick={() => editor.chain().focus().toggleHighlight().run()}
+        isActive={editor.isActive("highlight")}
+        title={`Highlight (${mod}${isMac ? "" : "+"}${shift}${isMac ? "" : "+"}H)`}
+      >
+        <HighlighterIcon className="w-4.5 h-4.5 stroke-[1.5]" />
+      </ToolbarButton>
 
       <div className="w-px h-4.5 border-l border-border mx-2" />
 
@@ -1098,6 +1107,7 @@ export function Editor({
         inline: false,
         allowBase64: false,
       }),
+      Highlight,
       TaskList,
       TaskItem.configure({
         nested: true,
diff --git a/src/components/icons/index.tsx b/src/components/icons/index.tsx
index 3e25c02b..7456c553 100644
--- a/src/components/icons/index.tsx
+++ b/src/components/icons/index.tsx
@@ -378,6 +378,26 @@ export function LinkOffIcon({ className = "w-4.5 h-4.5" }: IconProps) {
   );
 }
 
+export function HighlighterIcon({ className = "w-4.5 h-4.5" }: IconProps) {
+  return (
+    <svg
+      className={className}
+      fill="none"
+      stroke="currentColor"
+      viewBox="0 0 24 24"
+      strokeWidth={2}
+      strokeLinecap="round"
+      strokeLinejoin="round"
+    >
+      <path stroke="none" d="M0 0h24v24H0z" fill="none" />
+      <path d="M9 11l6 6l-3.5 3.5a2.121 2.121 0 0 1 -3 -3l.5 -.5" />
+      <path d="M11 6l6.5 6.5" />
+      <path d="M4 20h4.5" />
+      <path d="M13.5 6.5l3.5 -3.5l4 4l-3.5 3.5" />
+    </svg>
+  );
+}
+
 export function ImageIcon({ className = "w-4.5 h-4.5" }: IconProps) {
   return (
     <svg
diff --git a/src/lib/shortcuts.ts b/src/lib/shortcuts.ts
index a58c0ce9..028adeff 100644
--- a/src/lib/shortcuts.ts
+++ b/src/lib/shortcuts.ts
@@ -70,6 +70,7 @@ export const shortcutCategories: ShortcutCategory[] = [
       { keys: ["**bold**"], description: "Bold text" },
       { keys: ["*italic*"], description: "Italic text" },
       { keys: ["~~text~~"], description: "Strikethrough" },
+      { keys: ["==text=="], description: "Highlight" },
       { keys: ["-"], description: "Bullet list" },
       { keys: ["1."], description: "Numbered list" },
       { keys: ["- [ ]"], description: "Task list" },