diff --git a/.changeset/quiet-sidebar-padding.md b/.changeset/quiet-sidebar-padding.md
new file mode 100644
index 00000000000..f7d0deb0b3e
--- /dev/null
+++ b/.changeset/quiet-sidebar-padding.md
@@ -0,0 +1,5 @@
+---
+'@primer/react': patch
+---
+
+Fix `PageLayout.Sidebar` so its `padding` prop applies independently of the root layout padding.
diff --git a/packages/react/src/PageLayout/PageLayout.module.css b/packages/react/src/PageLayout/PageLayout.module.css
index 526fa6d8ee5..d2ca689e1f2 100644
--- a/packages/react/src/PageLayout/PageLayout.module.css
+++ b/packages/react/src/PageLayout/PageLayout.module.css
@@ -840,6 +840,8 @@
 .Sidebar {
   width: var(--pane-width-size);
   height: 100%;
+  /* stylelint-disable-next-line primer/spacing */
+  padding: var(--spacing);
   overflow: auto;
 
   &:where([data-resizable]) {
diff --git a/packages/react/src/PageLayout/PageLayout.sidebar-padding.test.tsx b/packages/react/src/PageLayout/PageLayout.sidebar-padding.test.tsx
new file mode 100644
index 00000000000..09082ce4f0d
--- /dev/null
+++ b/packages/react/src/PageLayout/PageLayout.sidebar-padding.test.tsx
@@ -0,0 +1,18 @@
+import {describe, it, expect} from 'vitest'
+import {render} from '@testing-library/react'
+import {PageLayout} from './PageLayout'
+
+describe('PageLayout.Sidebar padding', () => {
+  it('applies sidebar padding when the root has no padding', () => {
+    const {container} = render(
+      <PageLayout padding="none">
+        <PageLayout.Content>Content</PageLayout.Content>
+        <PageLayout.Sidebar padding="condensed">Sidebar</PageLayout.Sidebar>
+      </PageLayout>,
+    )
+
+    const sidebar = container.querySelector<HTMLElement>('[data-component="PageLayout.Sidebar"]')
+    expect(sidebar).not.toBeNull()
+    expect(getComputedStyle(sidebar!).paddingTop).toBe('16px')
+  })
+})