diff --git a/.changeset/honest-lamps-occur.md b/.changeset/honest-lamps-occur.md
new file mode 100644
index 0000000000..27b2eb44f5
--- /dev/null
+++ b/.changeset/honest-lamps-occur.md
@@ -0,0 +1,5 @@
+---
+'@backstage/ui': patch
+---
+
+Fixed dialog backdrop appearance in dark mode.
diff --git a/packages/ui/src/components/Dialog/Dialog.module.css b/packages/ui/src/components/Dialog/Dialog.module.css
index 22d96146ea..5101cbf67c 100644
--- a/packages/ui/src/components/Dialog/Dialog.module.css
+++ b/packages/ui/src/components/Dialog/Dialog.module.css
@@ -23,7 +23,7 @@
     left: 0;
     width: 100%;
     height: 100%;
-    background: rgba(232, 232, 232, 0.8);
+    background: color-mix(in srgb, var(--bui-gray-2) 80%, transparent);
     display: flex;
     align-items: center;
     justify-content: center;