diff --git a/dom/base/Document.cpp b/dom/base/Document.cpp
index a85d3e0bb9f4c..c0494f7ccc74d 100644
--- a/dom/base/Document.cpp
+++ b/dom/base/Document.cpp
@@ -1307,6 +1307,7 @@ Document::Document(const char* aContentType)
       mIsInitialDocumentInWindow(false),
       mIgnoreDocGroupMismatches(false),
       mLoadedAsData(false),
+      mAddedToMemoryReportingAsDataDocument(false),
       mMayStartLayout(true),
       mHaveFiredTitleChange(false),
       mIsShowing(false),
@@ -2239,6 +2240,8 @@ Document::~Document() {
   }
 
   UnlinkOriginalDocumentIfStatic();
+
+  UnregisterFromMemoryReportingForDataDocument();
 }
 
 NS_INTERFACE_TABLE_HEAD(Document)
@@ -2585,6 +2588,9 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(Document)
     tmp->mResizeObserverController->Unlink();
   }
   tmp->mMetaViewports.Clear();
+
+  tmp->UnregisterFromMemoryReportingForDataDocument();
+
   NS_IMPL_CYCLE_COLLECTION_UNLINK(mL10nProtoElements)
   NS_IMPL_CYCLE_COLLECTION_UNLINK_WEAK_PTR
   NS_IMPL_CYCLE_COLLECTION_UNLINK_WEAK_REFERENCE
@@ -3267,6 +3273,7 @@ nsresult Document::StartDocumentLoad(const char* aCommand, nsIChannel* aChannel,
 
   if (nsCRT::strcmp(kLoadAsData, aCommand) == 0) {
     mLoadedAsData = true;
+    SetLoadedAsData(true, /* aConsiderForMemoryReporting */ true);
     // We need to disable script & style loading in this case.
     // We leave them disabled even in EndLoad(), and let anyone
     // who puts the document on display to worry about enabling.
@@ -3436,6 +3443,20 @@ nsresult Document::StartDocumentLoad(const char* aCommand, nsIChannel* aChannel,
   return NS_OK;
 }
 
+void Document::SetLoadedAsData(bool aLoadedAsData,
+                               bool aConsiderForMemoryReporting) {
+  mLoadedAsData = aLoadedAsData;
+  if (aConsiderForMemoryReporting) {
+    nsIGlobalObject* global = GetScopeObject();
+    if (global) {
+      if (nsPIDOMWindowInner* window = global->AsInnerWindow()) {
+        nsGlobalWindowInner::Cast(window)
+            ->RegisterDataDocumentForMemoryReporting(this);
+      }
+    }
+  }
+}
+
 nsIContentSecurityPolicy* Document::GetCsp() const { return mCSP; }
 
 void Document::SetCsp(nsIContentSecurityPolicy* aCSP) { mCSP = aCSP; }
@@ -11722,7 +11743,9 @@ nsresult Document::CloneDocHelper(Document* clone) const {
     clone->SetScopeObject(GetScopeObject());
   }
   // Make the clone a data document
-  clone->SetLoadedAsData(true);
+  clone->SetLoadedAsData(
+      true,
+      /* aConsiderForMemoryReporting */ !mCreatingStaticClone);
 
   // Misc state
 
@@ -17279,4 +17302,17 @@ void Document::RemoveMediaElementWithMSE() {
   }
 }
 
+void Document::UnregisterFromMemoryReportingForDataDocument() {
+  if (!mAddedToMemoryReportingAsDataDocument) {
+    return;
+  }
+  mAddedToMemoryReportingAsDataDocument = false;
+  nsIGlobalObject* global = GetScopeObject();
+  if (global) {
+    if (nsPIDOMWindowInner* win = global->AsInnerWindow()) {
+      nsGlobalWindowInner::Cast(win)->UnregisterDataDocumentForMemoryReporting(
+          this);
+    }
+  }
+}
 }  // namespace mozilla::dom
diff --git a/dom/base/Document.h b/dom/base/Document.h
index dda4b70a0d93d..619484ceb2d07 100644
--- a/dom/base/Document.h
+++ b/dom/base/Document.h
@@ -1048,7 +1048,7 @@ class Document : public nsINode,
    */
   void SetIsInitialDocument(bool aIsInitialDocument);
 
-  void SetLoadedAsData(bool aLoadedAsData) { mLoadedAsData = aLoadedAsData; }
+  void SetLoadedAsData(bool aLoadedAsData, bool aConsiderForMemoryReporting);
 
   /**
    * Normally we assert if a runnable labeled with one DocGroup touches data
@@ -2519,6 +2519,12 @@ class Document : public nsINode,
 
   bool IsLoadedAsData() { return mLoadedAsData; }
 
+  void SetAddedToMemoryReportAsDataDocument() {
+    mAddedToMemoryReportingAsDataDocument = true;
+  }
+
+  void UnregisterFromMemoryReportingForDataDocument();
+
   bool MayStartLayout() { return mMayStartLayout; }
 
   void SetMayStartLayout(bool aMayStartLayout);
@@ -4486,6 +4492,10 @@ class Document : public nsINode,
   // as scripts and plugins, disabled.
   bool mLoadedAsData : 1;
 
+  // True if the document is considered for memory reporting as a
+  // data document
+  bool mAddedToMemoryReportingAsDataDocument : 1;
+
   // If true, whoever is creating the document has gotten it to the
   // point where it's safe to start layout on it.
   bool mMayStartLayout : 1;
diff --git a/dom/base/nsGlobalWindowInner.cpp b/dom/base/nsGlobalWindowInner.cpp
index 96749d44b9b20..fc3827e90511a 100644
--- a/dom/base/nsGlobalWindowInner.cpp
+++ b/dom/base/nsGlobalWindowInner.cpp
@@ -6646,6 +6646,29 @@ void nsGlobalWindowInner::AddSizeOfIncludingThis(
   }
 }
 
+void nsGlobalWindowInner::RegisterDataDocumentForMemoryReporting(
+    Document* aDocument) {
+  aDocument->SetAddedToMemoryReportAsDataDocument();
+  mDataDocumentsForMemoryReporting.AppendElement(
+      do_GetWeakReference(aDocument));
+}
+
+void nsGlobalWindowInner::UnregisterDataDocumentForMemoryReporting(
+    Document* aDocument) {
+  nsWeakPtr doc = do_GetWeakReference(aDocument);
+  MOZ_ASSERT(mDataDocumentsForMemoryReporting.Contains(doc));
+  mDataDocumentsForMemoryReporting.RemoveElement(doc);
+}
+
+void nsGlobalWindowInner::CollectDOMSizesForDataDocuments(
+    nsWindowSizes& aSize) const {
+  for (const nsWeakPtr& ptr : mDataDocumentsForMemoryReporting) {
+    if (nsCOMPtr<Document> doc = do_QueryReferent(ptr)) {
+      doc->DocAddSizeOfIncludingThis(aSize);
+    }
+  }
+}
+
 void nsGlobalWindowInner::AddGamepad(GamepadHandle aHandle, Gamepad* aGamepad) {
   // Create the index we will present to content based on which indices are
   // already taken, as required by the spec.
diff --git a/dom/base/nsGlobalWindowInner.h b/dom/base/nsGlobalWindowInner.h
index 5555f9f065db1..dc42df8287566 100644
--- a/dom/base/nsGlobalWindowInner.h
+++ b/dom/base/nsGlobalWindowInner.h
@@ -474,6 +474,10 @@ class nsGlobalWindowInner final : public mozilla::dom::EventTarget,
 
   void AddSizeOfIncludingThis(nsWindowSizes& aWindowSizes) const;
 
+  void CollectDOMSizesForDataDocuments(nsWindowSizes&) const;
+  void RegisterDataDocumentForMemoryReporting(Document*);
+  void UnregisterDataDocumentForMemoryReporting(Document*);
+
   enum SlowScriptResponse {
     ContinueSlowScript = 0,
     ContinueSlowScriptAndKeepNotifying,
@@ -1500,6 +1504,8 @@ class nsGlobalWindowInner final : public mozilla::dom::EventTarget,
 
   nsTArray<uint32_t> mScrollMarks;
 
+  nsTArray<nsWeakPtr> mDataDocumentsForMemoryReporting;
+
   static InnerWindowByIdTable* sInnerWindowsById;
 
   // Members in the mChromeFields member should only be used in chrome windows.
diff --git a/dom/base/nsWindowMemoryReporter.cpp b/dom/base/nsWindowMemoryReporter.cpp
index 268c7cac4b61b..24c0799b86534 100644
--- a/dom/base/nsWindowMemoryReporter.cpp
+++ b/dom/base/nsWindowMemoryReporter.cpp
@@ -330,6 +330,13 @@ static void CollectWindowReports(nsGlobalWindowInner* aWindow,
   ReportDOMSize(windowPath, aWindowTotalSizes->mDOMSizes, aHandleReport, aData,
                 windowSizes.mDOMSizes);
 
+  nsCString dataDocumentPath(windowPath);
+  dataDocumentPath += "/data-documents";
+  nsWindowSizes dataDocumentSizes(state);
+  aWindow->CollectDOMSizesForDataDocuments(dataDocumentSizes);
+  ReportDOMSize(dataDocumentPath, aWindowTotalSizes->mDOMSizes, aHandleReport,
+                aData, dataDocumentSizes.mDOMSizes);
+
   REPORT_SIZE("/layout/style-sheets", mLayoutStyleSheetsSize,
               "Memory used by document style sheets within a window.");
 
diff --git a/dom/base/test/browser.ini b/dom/base/test/browser.ini
index c8797954bb5a1..fcebe8d715519 100644
--- a/dom/base/test/browser.ini
+++ b/dom/base/test/browser.ini
@@ -89,3 +89,4 @@ support-files =
 [browser_bug1703472.js]
 support-files =
   file_bug1703472.html
+[browser_data_documents_aboutmemory.js]
diff --git a/dom/base/test/browser_data_documents_aboutmemory.js b/dom/base/test/browser_data_documents_aboutmemory.js
new file mode 100644
index 0000000000000..a960ecb806879
--- /dev/null
+++ b/dom/base/test/browser_data_documents_aboutmemory.js
@@ -0,0 +1,20 @@
+add_task(async function() {
+  const doc = new DOMParser().parseFromString("<p>dadada</p>", "text/html");
+
+  let mgr = Cc["@mozilla.org/memory-reporter-manager;1"].getService(
+    Ci.nsIMemoryReporterManager
+  );
+
+  let amount = 0;
+  const handleReport = (aProcess, aPath, aKind, aUnits, aAmount) => {
+    const regex = new RegExp(".*/window-objects/.*/data-documents/.*");
+    if (regex.test(aPath)) {
+      amount += aAmount;
+    }
+  };
+
+  await new Promise(r =>
+    mgr.getReports(handleReport, null, r, null, /* anonymized = */ false)
+  );
+  ok(amount > 0, "Got data documents amount");
+});
diff --git a/dom/html/nsHTMLDocument.cpp b/dom/html/nsHTMLDocument.cpp
index 675d32bbb15cb..723af36a0bef4 100644
--- a/dom/html/nsHTMLDocument.cpp
+++ b/dom/html/nsHTMLDocument.cpp
@@ -115,7 +115,7 @@ nsresult NS_NewHTMLDocument(Document** aInstancePtrResult, bool aLoadedAsData) {
     return rv;
   }
 
-  doc->SetLoadedAsData(aLoadedAsData);
+  doc->SetLoadedAsData(aLoadedAsData, /* aConsiderForMemoryReporting */ true);
   doc.forget(aInstancePtrResult);
 
   return NS_OK;
diff --git a/dom/xml/XMLDocument.cpp b/dom/xml/XMLDocument.cpp
index bf33993f7987b..c76adeaf925be 100644
--- a/dom/xml/XMLDocument.cpp
+++ b/dom/xml/XMLDocument.cpp
@@ -118,7 +118,7 @@ nsresult NS_NewDOMDocument(Document** aInstancePtrResult,
     d->SetCompatibilityMode(eCompatibility_FullStandards);
     d->AsHTMLDocument()->SetIsXHTML(isXHTML);
   }
-  d->SetLoadedAsData(aLoadedAsData);
+  d->SetLoadedAsData(aLoadedAsData, /* aConsiderForMemoryReporting */ true);
   d->SetDocumentURI(aDocumentURI);
   // Must set the principal first, since SetBaseURI checks it.
   d->SetPrincipals(aPrincipal, aPrincipal);
@@ -185,7 +185,7 @@ nsresult NS_NewXMLDocument(Document** aInstancePtrResult, bool aLoadedAsData,
     return rv;
   }
 
-  doc->SetLoadedAsData(aLoadedAsData);
+  doc->SetLoadedAsData(aLoadedAsData, /* aConsiderForMemoryReporting */ true);
   doc->mIsPlainDocument = aIsPlainDocument;
   doc.forget(aInstancePtrResult);