--- a/browser/components/enterprisepolicies/EnterprisePolicies.js
+++ b/browser/components/enterprisepolicies/EnterprisePolicies.js
@@ -2,16 +2,17 @@
  * 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/. */
 
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.import("resource://gre/modules/AppConstants.jsm");
 
 XPCOMUtils.defineLazyModuleGetters(this, {
+  WindowsGPOParser: "resource:///modules/policies/WindowsGPOParser.jsm",
   NetUtil: "resource://gre/modules/NetUtil.jsm",
   Policies: "resource:///modules/policies/Policies.jsm",
   PoliciesValidator: "resource:///modules/policies/PoliciesValidator.jsm",
 });
 
 // This is the file that will be searched for in the
 // ${InstallDir}/distribution folder.
 const POLICIES_FILENAME = "policies.json";
@@ -95,17 +96,22 @@ EnterprisePoliciesManager.prototype = {
       return;
     }
 
     this.status = Ci.nsIEnterprisePolicies.ACTIVE;
     this._activatePolicies(provider.policies);
   },
 
   _chooseProvider() {
-    // TODO: Bug 1433136 - Add GPO provider with higher precendence here
+    if (AppConstants.platform == "win") {
+      let gpoProvider = new GPOPoliciesProvider();
+      if (gpoProvider.hasPolicies) {
+        return gpoProvider;
+      }
+    }
 
     let jsonProvider = new JSONPoliciesProvider();
     if (jsonProvider.hasPolicies) {
       return jsonProvider;
     }
 
     return null;
   },
@@ -361,11 +367,51 @@ class JSONPoliciesProvider {
       } else {
         log.error("Error reading file");
         this._failed = true;
       }
     }
   }
 }
 
+class GPOPoliciesProvider {
+  constructor() {
+    this._policies = null;
+
+    let wrk = Cc["@mozilla.org/windows-registry-key;1"].createInstance(Ci.nsIWindowsRegKey);
+    // Machine policies override user policies, so we read
+    // user policies first and then replace them if necessary.
+    wrk.open(wrk.ROOT_KEY_CURRENT_USER,
+             "SOFTWARE\\Policies",
+             wrk.ACCESS_READ);
+    if (wrk.hasChild("Mozilla\\Firefox")) {
+      this._readData(wrk);
+    }
+    wrk.close();
+
+    wrk.open(wrk.ROOT_KEY_LOCAL_MACHINE,
+             "SOFTWARE\\Policies",
+             wrk.ACCESS_READ);
+    if (wrk.hasChild("Mozilla\\Firefox")) {
+      this._readData(wrk);
+    }
+    wrk.close();
+  }
+
+  get hasPolicies() {
+    return this._policies !== null;
+  }
+
+  get policies() {
+    return this._policies;
+  }
+
+  get failed() {
+    return this._failed;
+  }
+
+  _readData(wrk) {
+    this._policies = WindowsGPOParser.readPolicies(wrk, this._policies);
+  }
+}
 
 var components = [EnterprisePoliciesManager];
 this.NSGetFactory = XPCOMUtils.generateNSGetFactory(components);

new file mode 100644
--- /dev/null
+++ b/browser/components/enterprisepolicies/WindowsGPOParser.jsm
@@ -0,0 +1,97 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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/. */
+
+"use strict";
+
+ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
+
+const PREF_LOGLEVEL = "browser.policies.loglevel";
+
+XPCOMUtils.defineLazyGetter(this, "log", () => {
+  let { ConsoleAPI } = ChromeUtils.import("resource://gre/modules/Console.jsm", {});
+  return new ConsoleAPI({
+    prefix: "GPOParser.jsm",
+    // tip: set maxLogLevel to "debug" and use log.debug() to create detailed
+    // messages during development. See LOG_LEVELS in Console.jsm for details.
+    maxLogLevel: "error",
+    maxLogLevelPref: PREF_LOGLEVEL,
+  });
+});
+
+this.EXPORTED_SYMBOLS = ["WindowsGPOParser"];
+
+this.WindowsGPOParser = {
+  readPolicies(wrk, policies) {
+    let childWrk = wrk.openChild("Mozilla\\Firefox", wrk.ACCESS_READ);
+    if (!policies) {
+      policies = {};
+    }
+    try {
+      policies = registryToObject(childWrk, policies);
+    } catch (e) {
+      log.error(e);
+    } finally {
+      childWrk.close();
+    }
+    return policies;
+  }
+};
+
+function registryToObject(wrk, policies) {
+  if (!policies) {
+    policies = {};
+  }
+  if (wrk.valueCount > 0) {
+    if (wrk.getValueName(0) == "1") {
+      // If the first item is 1, just assume it is an array
+      let array = [];
+      for (let i = 0; i < wrk.valueCount; i++) {
+        array.push(readRegistryValue(wrk, wrk.getValueName(i)));
+      }
+      // If it's an array, it shouldn't have any children
+      return array;
+    }
+    for (let i = 0; i < wrk.valueCount; i++) {
+      let name = wrk.getValueName(i);
+      let value = readRegistryValue(wrk, name);
+      policies[name] = value;
+    }
+  }
+  if (wrk.childCount > 0) {
+    if (wrk.getChildName(0) == "1") {
+      // If the first item is 1, it's an array of objects
+      let array = [];
+      for (let i = 0; i < wrk.childCount; i++) {
+        let name = wrk.getChildName(i);
+        let childWrk = wrk.openChild(name, wrk.ACCESS_READ);
+        array.push(registryToObject(childWrk));
+        childWrk.close();
+      }
+      // If it's an array, it shouldn't have any children
+      return array;
+    }
+    for (let i = 0; i < wrk.childCount; i++) {
+      let name = wrk.getChildName(i);
+      let childWrk = wrk.openChild(name, wrk.ACCESS_READ);
+      policies[name] = registryToObject(childWrk);
+      childWrk.close();
+    }
+  }
+  return policies;
+}
+
+function readRegistryValue(wrk, value) {
+  switch (wrk.getValueType(value)) {
+    case wrk.TYPE_STRING:
+     return wrk.readStringValue(value);
+    case wrk.TYPE_BINARY:
+      return wrk.readBinaryValue(value);
+    case wrk.TYPE_INT:
+      return wrk.readIntValue(value);
+    case wrk.TYPE_INT64:
+      return wrk.readInt64Value(value);
+  }
+  // unknown type
+  return null;
+}

--- a/browser/components/enterprisepolicies/moz.build
+++ b/browser/components/enterprisepolicies/moz.build
@@ -22,9 +22,14 @@ EXTRA_COMPONENTS += [
     'EnterprisePoliciesContent.js',
 ]
 
 EXTRA_JS_MODULES.policies += [
     'Policies.jsm',
     'PoliciesValidator.jsm',
 ]
 
+if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'windows':
+    EXTRA_JS_MODULES.policies += [
+        'WindowsGPOParser.jsm',
+]
+
 FINAL_LIBRARY = 'browsercomps'