diff --git a/app/assets/stylesheets/page_bundles/ide.scss b/app/assets/stylesheets/page_bundles/ide.scss
index a80158943c6..0c1067bfacc 100644
--- a/app/assets/stylesheets/page_bundles/ide.scss
+++ b/app/assets/stylesheets/page_bundles/ide.scss
@@ -179,6 +179,14 @@ $ide-commit-header-height: 48px;
     display: none;
   }
 
+  .monaco-editor .selected-text {
+    z-index: 1;
+  }
+
+  .monaco-editor .view-lines {
+    z-index: 2;
+  }
+
   .is-readonly,
   .editor.original {
     .view-lines {
diff --git a/changelogs/unreleased/47771-highlighting-in-diff.yml b/changelogs/unreleased/47771-highlighting-in-diff.yml
new file mode 100644
index 00000000000..a8e8cbf0174
--- /dev/null
+++ b/changelogs/unreleased/47771-highlighting-in-diff.yml
@@ -0,0 +1,5 @@
+---
+title: Enabled text selection highlighting in diffs in Web IDE
+merge_request: 26721
+author: Isaac Smith
+type: fixed