diff --git a/UNRELEASED.md b/UNRELEASED.md
index 5c68e1f7cfa..b7d95948991 100644
--- a/UNRELEASED.md
+++ b/UNRELEASED.md
@@ -53,3 +53,4 @@ Use [the changelog guidelines](/documentation/Versioning%20and%20changelog.md) t
 ### Deprecations
 
 - Deprecated passing `attention` to the `status` prop on `Badge` in favor of `warning` ([#4658](https://github.com/Shopify/polaris-react/pull/4658))
+- Deprecated `thumbnail` property for `Page` ([#4733](https://github.com/Shopify/polaris-react/pull/4733))
diff --git a/src/components/Page/components/Header/components/Title/Title.tsx b/src/components/Page/components/Header/components/Title/Title.tsx
index 4ea1386278f..8771d129900 100644
--- a/src/components/Page/components/Header/components/Title/Title.tsx
+++ b/src/components/Page/components/Header/components/Title/Title.tsx
@@ -13,7 +13,7 @@ export interface TitleProps {
   subtitle?: string;
   /** Important and non-interactive status information shown immediately after the title. */
   titleMetadata?: React.ReactNode;
-  /** thumbnail that precedes the title */
+  /** @deprecated thumbnail that precedes the title */
   thumbnail?:
     | React.ReactElement<AvatarProps | ThumbnailProps>
     | React.SFC<React.SVGProps<SVGSVGElement>>;
@@ -28,6 +28,11 @@ export function Title({
   thumbnail,
   compactTitle,
 }: TitleProps) {
+  if (process.env.NODE_ENV === 'development' && thumbnail != null) {
+    // eslint-disable-next-line no-console
+    console.warn('The thumbnail prop from Page has been deprecated');
+  }
+
   const titleMarkup = title ? <h1 className={styles.Title}>{title}</h1> : null;
 
   const titleMetadataMarkup = titleMetadata ? (