diff --git a/.changeset/few-papayas-brush.md b/.changeset/few-papayas-brush.md
new file mode 100644
index 00000000000..9fdd91d845c
--- /dev/null
+++ b/.changeset/few-papayas-brush.md
@@ -0,0 +1,5 @@
+---
+'@primer/react': patch
+---
+
+UnderlineNav2: Add a z-index to make it appear on the top of the stack
diff --git a/src/UnderlineNav2/styles.ts b/src/UnderlineNav2/styles.ts
index d3167a5f8e9..8ce978d02d6 100644
--- a/src/UnderlineNav2/styles.ts
+++ b/src/UnderlineNav2/styles.ts
@@ -147,6 +147,7 @@ export const menuItemStyles = {
 
 export const menuStyles = {
   position: 'absolute',
+  zIndex: 1,
   top: '90%',
   right: '0',
   boxShadow: '0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24)',