diff --git a/CHANGELOG.md b/CHANGELOG.md
index 237f011d81..d955d0af22 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@ and this project adheres to
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+- 🐛(frontend) hide source popup in read-only mode #2908
 
 ## [v6.0.4] - 2026-10-26
 
diff --git a/src/frontend/apps/impress/src/features/docs/doc-editor/styles.tsx b/src/frontend/apps/impress/src/features/docs/doc-editor/styles.tsx
index b39311a847..f8d4dfae37 100644
--- a/src/frontend/apps/impress/src/features/docs/doc-editor/styles.tsx
+++ b/src/frontend/apps/impress/src/features/docs/doc-editor/styles.tsx
@@ -68,6 +68,15 @@ export const DocsEditorStyle = createGlobalStyle`
       pointer-events: none;
     }
 
+    /**
+     * Read-only and presentation mode: visually hide the source popup of math
+     * and diagram blocks. (BlockNote opens it from the selection even when
+     *  the editor is not editable, so this only hides it and does not prevent it).
+     */
+    .bn-editor:not([contenteditable='true']) .bn-source-block-popup {
+      display: none;
+    }
+
     /**
     * Collaboration cursor styles
     */