diff --git a/toolkit/webapps/WebappOSUtils.jsm b/toolkit/webapps/WebappOSUtils.jsm
index 2c7c09e9d9cd..56ca9c5ee68c 100644
--- a/toolkit/webapps/WebappOSUtils.jsm
+++ b/toolkit/webapps/WebappOSUtils.jsm
@@ -2,10 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-const Cc = Components.classes;
-const Ci = Components.interfaces;
-const CC = Components.Constructor;
-const Cu = Components.utils;
+const { classes: Cc, interfaces: Ci, results: Cr, utils: Cu, Constructor: CC } = Components;
 
 Cu.import("resource://gre/modules/Services.jsm");
 Cu.import("resource://gre/modules/FileUtils.jsm");
@@ -119,8 +116,8 @@ this.WebappOSUtils = {
 #elifdef XP_MACOSX
     let uniqueName = this.getUniqueName(aApp);
 
-    let mwaUtils = Cc["@mozilla.org/widget/mac-web-app-utils;1"]
-                     .createInstance(Ci.nsIMacWebAppUtils);
+    let mwaUtils = Cc["@mozilla.org/widget/mac-web-app-utils;1"].
+                   createInstance(Ci.nsIMacWebAppUtils);
 
     try {
       let path;
@@ -265,8 +262,8 @@ this.WebappOSUtils = {
       return false;
     }
 
-    let mwaUtils = Cc["@mozilla.org/widget/mac-web-app-utils;1"]
-                     .createInstance(Ci.nsIMacWebAppUtils);
+    let mwaUtils = Cc["@mozilla.org/widget/mac-web-app-utils;1"].
+                   createInstance(Ci.nsIMacWebAppUtils);
 
     try {
       mwaUtils.launchAppWithIdentifier(launchIdentifier);
@@ -331,7 +328,25 @@ this.WebappOSUtils = {
 
     return deferred.promise;
 #elifdef XP_MACOSX
-    return Promise.reject("Uninstallation not yet implemented");
+    let [ , path ] = this.getLaunchTarget(aApp);
+    if (!path) {
+      return Promise.reject("App not found");
+    }
+
+    let deferred = Promise.defer();
+
+    let mwaUtils = Cc["@mozilla.org/widget/mac-web-app-utils;1"].
+                   createInstance(Ci.nsIMacWebAppUtils);
+
+    mwaUtils.trashApp(path, (aResult) => {
+      if (aResult == Cr.NS_OK) {
+        deferred.resolve(true);
+      } else {
+        deferred.resolve("Error moving the app to the Trash: " + aResult);
+      }
+    });
+
+    return deferred.promise;
 #elifdef XP_UNIX
     let exeFile = this.getLaunchTarget(aApp);
     if (!exeFile) {
diff --git a/widget/cocoa/nsMacWebAppUtils.mm b/widget/cocoa/nsMacWebAppUtils.mm
index f37cde8215f5..cc96abf8ed70 100644
--- a/widget/cocoa/nsMacWebAppUtils.mm
+++ b/widget/cocoa/nsMacWebAppUtils.mm
@@ -57,3 +57,26 @@ NS_IMETHODIMP nsMacWebAppUtils::LaunchAppWithIdentifier(const nsAString& bundleI
 
   NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;
 }
+
+NS_IMETHODIMP nsMacWebAppUtils::TrashApp(const nsAString& path, nsITrashAppCallback* aCallback) {
+  NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT;
+
+  if (NS_WARN_IF(!aCallback)) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsCOMPtr<nsITrashAppCallback> callback = aCallback;
+
+  NSString* tempString = [NSString stringWithCharacters:reinterpret_cast<const unichar*>(((nsString)path).get())
+                                   length:path.Length()];
+
+  [[NSWorkspace sharedWorkspace] recycleURLs: [NSArray arrayWithObject:[NSURL fileURLWithPath:tempString]]
+    completionHandler: ^(NSDictionary *newURLs, NSError *error) {
+      nsresult rv = (error == nil) ? NS_OK : NS_ERROR_FAILURE;
+      callback->TrashAppFinished(rv);
+    }];
+
+  return NS_OK;
+
+  NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;
+}
diff --git a/widget/nsIMacWebAppUtils.idl b/widget/nsIMacWebAppUtils.idl
index 12a42ea17c10..4d570a8bf0eb 100644
--- a/widget/nsIMacWebAppUtils.idl
+++ b/widget/nsIMacWebAppUtils.idl
@@ -6,11 +6,17 @@
 
 interface nsIMacWebAppUtils;
 
+[scriptable, function, uuid(8c899c4f-58c1-4b74-9034-3bb64e484b68)]
+interface nsITrashAppCallback : nsISupports
+{
+  void trashAppFinished(in nsresult rv);
+};
+
 /**
  * Allow MozApps API to locate and manipulate natively installed apps
  */
 
-[scriptable, uuid(e9096367-ddd9-45e4-b762-49c0c18b7119)]
+[scriptable, uuid(c69cf343-ea41-428b-b161-4655fd54d8e7)]
 interface nsIMacWebAppUtils : nsISupports {
   /**
    * Find the path for an app with the given signature.
@@ -22,4 +28,8 @@ interface nsIMacWebAppUtils : nsISupports {
    */
   void launchAppWithIdentifier(in AString bundleIdentifier);
 
+  /**
+   * Move the app from the given directory to the Trash.
+   */
+  void trashApp(in AString path, in nsITrashAppCallback callback);
 };