diff --git a/toolkit/components/alerts/AlertNotification.cpp b/toolkit/components/alerts/AlertNotification.cpp
index ef443f714a8..b72e5746adb 100644
--- a/toolkit/components/alerts/AlertNotification.cpp
+++ b/toolkit/components/alerts/AlertNotification.cpp
@@ -117,6 +117,16 @@ AlertNotification::GetPrincipal(nsIPrincipal** aPrincipal)
   return NS_OK;
 }
 
+NS_IMETHODIMP
+AlertNotification::GetURI(nsIURI** aURI)
+{
+  if (!nsAlertsUtils::IsActionablePrincipal(mPrincipal)) {
+    *aURI = nullptr;
+    return NS_OK;
+  }
+  return mPrincipal->GetURI(aURI);
+}
+
 NS_IMETHODIMP
 AlertNotification::GetInPrivateBrowsing(bool* aInPrivateBrowsing)
 {
diff --git a/toolkit/components/alerts/nsAlertsService.cpp b/toolkit/components/alerts/nsAlertsService.cpp
index d6765770ecb..345f6075406 100644
--- a/toolkit/components/alerts/nsAlertsService.cpp
+++ b/toolkit/components/alerts/nsAlertsService.cpp
@@ -22,10 +22,118 @@
 
 #endif // !MOZ_WIDGET_ANDROID
 
+#ifdef MOZ_PLACES
+#include "mozIAsyncFavicons.h"
+#include "nsIFaviconService.h"
+#endif // MOZ_PLACES
+
 using namespace mozilla;
 
 using mozilla::dom::ContentChild;
 
+namespace {
+
+#ifdef MOZ_PLACES
+
+class IconCallback final : public nsIFaviconDataCallback
+{
+public:
+  NS_DECL_ISUPPORTS
+
+  IconCallback(nsIAlertsService* aBackend,
+               nsIAlertNotification* aAlert,
+               nsIObserver* aAlertListener)
+    : mBackend(aBackend)
+    , mAlert(aAlert)
+    , mAlertListener(aAlertListener)
+  {}
+
+  NS_IMETHOD
+  OnComplete(nsIURI *aIconURI, uint32_t aIconSize, const uint8_t *aIconData,
+             const nsACString &aMimeType) override
+  {
+    nsresult rv = NS_ERROR_FAILURE;
+    if (aIconSize > 0) {
+      nsCOMPtr<nsIAlertsIconData> alertsIconData(do_QueryInterface(mBackend));
+      if (alertsIconData) {
+        rv = alertsIconData->ShowAlertWithIconData(mAlert, mAlertListener,
+                                                   aIconSize, aIconData);
+      }
+    } else if (aIconURI) {
+      nsCOMPtr<nsIAlertsIconURI> alertsIconURI(do_QueryInterface(mBackend));
+      if (alertsIconURI) {
+        rv = alertsIconURI->ShowAlertWithIconURI(mAlert, mAlertListener,
+                                                 aIconURI);
+      }
+    }
+    if (NS_FAILED(rv)) {
+      rv = mBackend->ShowAlert(mAlert, mAlertListener);
+    }
+    return rv;
+  }
+
+private:
+  virtual ~IconCallback() {}
+
+  nsCOMPtr<nsIAlertsService> mBackend;
+  nsCOMPtr<nsIAlertNotification> mAlert;
+  nsCOMPtr<nsIObserver> mAlertListener;
+};
+
+NS_IMPL_ISUPPORTS(IconCallback, nsIFaviconDataCallback)
+
+#endif // MOZ_PLACES
+
+nsresult
+ShowWithIconBackend(nsIAlertsService* aBackend, nsIAlertNotification* aAlert,
+                    nsIObserver* aAlertListener)
+{
+#ifdef MOZ_PLACES
+  nsCOMPtr<nsIURI> uri;
+  nsresult rv = aAlert->GetURI(getter_AddRefs(uri));
+  if (NS_FAILED(rv) || !uri) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Ensure the backend supports favicons.
+  nsCOMPtr<nsIAlertsIconData> alertsIconData(do_QueryInterface(aBackend));
+  nsCOMPtr<nsIAlertsIconURI> alertsIconURI;
+  if (!alertsIconData) {
+    alertsIconURI = do_QueryInterface(aBackend);
+  }
+  if (!alertsIconData && !alertsIconURI) {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  nsCOMPtr<mozIAsyncFavicons> favicons(do_GetService(
+    "@mozilla.org/browser/favicon-service;1"));
+  NS_ENSURE_TRUE(favicons, NS_ERROR_FAILURE);
+
+  nsCOMPtr<nsIFaviconDataCallback> callback =
+    new IconCallback(aBackend, aAlert, aAlertListener);
+  if (alertsIconData) {
+    return favicons->GetFaviconDataForPage(uri, callback);
+  }
+  return favicons->GetFaviconURLForPage(uri, callback);
+#else
+  return NS_ERROR_NOT_IMPLEMENTED;
+#endif // !MOZ_PLACES
+}
+
+nsresult
+ShowWithBackend(nsIAlertsService* aBackend, nsIAlertNotification* aAlert,
+                nsIObserver* aAlertListener)
+{
+  nsresult rv = ShowWithIconBackend(aBackend, aAlert, aAlertListener);
+  if (NS_SUCCEEDED(rv)) {
+    return rv;
+  }
+  // If the backend doesn't support favicons, show the alert without one.
+  return aBackend->ShowAlert(aAlert, aAlertListener);
+}
+
+} // anonymous namespace
+
 NS_IMPL_ISUPPORTS(nsAlertsService, nsIAlertsService, nsIAlertsDoNotDisturb, nsIAlertsProgressListener)
 
 nsAlertsService::nsAlertsService() :
@@ -66,7 +174,7 @@ bool nsAlertsService::ShouldShowAlert()
   return result;
 }
 
-NS_IMETHODIMP nsAlertsService::ShowAlertNotification(const nsAString & aImageUrl, const nsAString & aAlertTitle, 
+NS_IMETHODIMP nsAlertsService::ShowAlertNotification(const nsAString & aImageUrl, const nsAString & aAlertTitle,
                                                      const nsAString & aAlertText, bool aAlertTextClickable,
                                                      const nsAString & aAlertCookie,
                                                      nsIObserver * aAlertListener,
@@ -135,7 +243,7 @@ NS_IMETHODIMP nsAlertsService::ShowAlert(nsIAlertNotification * aAlert,
 #else
   // Check if there is an optional service that handles system-level notifications
   if (mBackend) {
-    rv = mBackend->ShowAlert(aAlert, aAlertListener);
+    rv = ShowWithBackend(mBackend, aAlert, aAlertListener);
     if (NS_SUCCEEDED(rv)) {
       return rv;
     }
@@ -154,7 +262,7 @@ NS_IMETHODIMP nsAlertsService::ShowAlert(nsIAlertNotification * aAlert,
   // Use XUL notifications as a fallback if above methods have failed.
   nsCOMPtr<nsIAlertsService> xulBackend(nsXULAlerts::GetInstance());
   NS_ENSURE_TRUE(xulBackend, NS_ERROR_FAILURE);
-  return xulBackend->ShowAlert(aAlert, aAlertListener);
+  return ShowWithBackend(xulBackend, aAlert, aAlertListener);
 #endif // !MOZ_WIDGET_ANDROID
 }
 
diff --git a/toolkit/components/alerts/nsIAlertsService.idl b/toolkit/components/alerts/nsIAlertsService.idl
index f11848f566e..d34061ff21b 100644
--- a/toolkit/components/alerts/nsIAlertsService.idl
+++ b/toolkit/components/alerts/nsIAlertsService.idl
@@ -7,12 +7,13 @@
 #include "nsIObserver.idl"
 
 interface nsIPrincipal;
+interface nsIURI;
 
 %{C++
 #define ALERT_NOTIFICATION_CONTRACTID "@mozilla.org/alert-notification;1"
 %}
 
-[scriptable, uuid(9e87fc34-8dbb-4b14-a724-b27be6822ec8)]
+[scriptable, uuid(1650a064-79d5-4eb6-8c9e-57dd6522b6ac)]
 interface nsIAlertNotification : nsISupports
 {
   /** Initializes an alert notification. */
@@ -85,6 +86,12 @@ interface nsIAlertNotification : nsISupports
    */
   readonly attribute nsIPrincipal principal;
 
+  /**
+   * The URI of the page that created the alert. |null| if the alert is not
+   * actionable.
+   */
+  readonly attribute nsIURI URI;
+
   /**
    * Controls the image loading behavior. If true, the image URL will be loaded
    * in private browsing mode.
@@ -224,3 +231,30 @@ interface nsIAlertsProgressListener : nsISupports
   void onCancel(in AString name);
 };
 
+[scriptable, uuid(fc6d7f0a-0cf6-4268-8c71-ab640842b9b1)]
+interface nsIAlertsIconData : nsISupports
+{
+  /**
+   * Shows an alert with an icon. Web notifications use the favicon of the
+   * page that created the alert. If the favicon is not in the Places database,
+   * |iconSize| will be zero.
+  */
+  void showAlertWithIconData(in nsIAlertNotification alert,
+                             [optional] in nsIObserver alertListener,
+                             [optional] in uint32_t iconSize,
+                             [const, array, size_is(iconSize)] in uint8_t
+                                                               iconData);
+};
+
+[scriptable, uuid(f3c82915-bf60-41ea-91ce-6c46b22e381a)]
+interface nsIAlertsIconURI : nsISupports
+{
+  /**
+   * Shows an alert with an icon URI. Web notifications use |moz-anno:|
+   * URIs to reference favicons from Places. If the page doesn't have a
+   * favicon, |iconURI| will be |null|.
+   */
+  void showAlertWithIconURI(in nsIAlertNotification alert,
+                            [optional] in nsIObserver alertListener,
+                            [optional] in nsIURI iconURI);
+};