diff --git a/.changeset/common-coins-stare.md b/.changeset/common-coins-stare.md
new file mode 100644
index 0000000000..0bd0078cf9
--- /dev/null
+++ b/.changeset/common-coins-stare.md
@@ -0,0 +1,7 @@
+---
+'@backstage/ui': patch
+---
+
+Fixed `ButtonIcon` incorrectly applying `className` to inner elements instead of only the root element.
+
+Affected components: ButtonIcon
diff --git a/.patches/pr-31900.txt b/.patches/pr-31900.txt
new file mode 100644
index 0000000000..43616d0e98
--- /dev/null
+++ b/.patches/pr-31900.txt
@@ -0,0 +1 @@
+Fix incorrectly applying className to three elements internally in ButtonIcon.
\ No newline at end of file
diff --git a/packages/ui/src/components/ButtonIcon/ButtonIcon.tsx b/packages/ui/src/components/ButtonIcon/ButtonIcon.tsx
index d3596da799..9bbeca9d5b 100644
--- a/packages/ui/src/components/ButtonIcon/ButtonIcon.tsx
+++ b/packages/ui/src/components/ButtonIcon/ButtonIcon.tsx
@@ -64,7 +64,6 @@ export const ButtonIcon = forwardRef(
                 classNamesButtonIcon.content,
                 stylesButton[classNames.content],
                 stylesButtonIcon[classNamesButtonIcon.content],
-                className,
               )}
             >
               {icon}
@@ -79,7 +78,6 @@ export const ButtonIcon = forwardRef(
                   classNamesButtonIcon.spinner,
                   stylesButton[classNames.spinner],
                   stylesButtonIcon[classNamesButtonIcon.spinner],
-                  className,
                 )}
               >
                 <RiLoader4Line aria-hidden="true" />