diff --git a/og_context/js/og_context.ajax.js b/og_context/js/og_context.ajax.js
new file mode 100644
index 0000000..b252a60
--- /dev/null
+++ b/og_context/js/og_context.ajax.js
@@ -0,0 +1,39 @@
+(function ($) {
+
+/**
+ * Adds Organic Groups GET variables to jQuery Ajax request URLs.
+ */
+Drupal.behaviors.ogContext = {
+  attach: function (context, settings) {
+    if (Drupal.settings.ogContext) {
+      // The only reliable way to modify an Ajax request to add GET variables
+      // seems to be to override the jQuery.ajax() function entirely. See
+      // https://stackoverflow.com/questions/2332305/modifying-a-jquery-ajax-request-intercepted-via-ajaxsend
+      var jQueryAjax = $.ajax;
+      $.ajax = function (settings_or_url, settings) {
+        // jQuery allows this function to be called as either $.ajax(settings)
+        // or $.ajax(url, settings), so handle both cases here.
+        if (typeof settings_or_url === 'string') {
+          if (typeof settings === 'undefined') {
+            settings = {};
+          }
+          settings.url = settings_or_url;
+        }
+        else {
+          settings = settings_or_url;
+        }
+
+        // Modify the Ajax request URL to add the GET variable, but only if the
+        // request is being made to a URL on this site.
+        if (typeof settings.url !== 'undefined' && Drupal.urlIsLocal(settings.url)) {
+          settings.url += settings.url.indexOf('?') >= 0 ? '&' : '?';
+          settings.url += 'og_ajax_context__gid=' + Drupal.settings.ogContext.gid + '&og_ajax_context__group_type=' + Drupal.settings.ogContext.groupType;
+        }
+
+        jQueryAjax(settings);
+      };
+    }
+  }
+};
+
+})(jQuery);
diff --git a/og_context/og_context.admin.inc b/og_context/og_context.admin.inc
index 027f94b..fe32098 100644
--- a/og_context/og_context.admin.inc
+++ b/og_context/og_context.admin.inc
@@ -44,8 +44,8 @@ function _og_context_configure_form_table(&$form) {
   );
 
   $group_context_providers = $form['#group_context_providers'];
-  // Enable url and node context handlers by default.
-  $defaults = array('url' => -5, 'node' => -4);
+  // Enable URL, node, and Ajax context handlers by default.
+  $defaults = array('url' => -5, 'node' => -4, 'ajax-request' => -3);
   $enabled_providers = variable_get("og_context_negotiation_$type", $defaults);
   $providers_weight = variable_get("og_context_providers_weight_$type", $defaults);
 
diff --git a/og_context/og_context.info b/og_context/og_context.info
index 5e4e792..5416e90 100644
--- a/og_context/og_context.info
+++ b/og_context/og_context.info
@@ -3,6 +3,7 @@ description = "Get a group from a viewed page."
 package = "Organic groups"
 dependencies[] = og
 core = 7.x
+scripts[] = js/og_context.ajax.js
 files[] = og_context.module
 files[] = og_context.install
 
diff --git a/og_context/og_context.module b/og_context/og_context.module
index 47df9b0..eb88be2 100644
--- a/og_context/og_context.module
+++ b/og_context/og_context.module
@@ -145,6 +145,12 @@ function og_context_og_context_negotiation_info() {
     'menu path' => array('comment/reply/%', 'comment/%'),
   );
 
+  $providers['ajax-request'] = array(
+    'name' => t('URL (Ajax request)'),
+    'description' => t('Determines context during Ajax requests by checking the group that was passed in via the URL by the page that made the Ajax request.'),
+    'callback' => 'og_context_handler_ajax_request',
+  );
+
   return $providers;
 }
 
@@ -405,8 +411,8 @@ function og_context_provider_weight($provider) {
  *   The group ID for the current context, or FALSE if not found.
  */
 function og_context_determine_context($group_type, $item = NULL, $check_access = TRUE) {
-  // Enable url and node context handlers by default.
-  $defaults = array('url' => -5, 'node' => -4);
+  // Enable URL, node, and Ajax context handlers by default.
+  $defaults = array('url' => -5, 'node' => -4, 'ajax-request' => -3);
   if (!$enabled_providers = variable_get('og_context_negotiation_group_context', $defaults)) {
     return;
   }
@@ -651,6 +657,19 @@ function _group_context_handler_entity($entity_type = 'node', $entity = NULL, $p
 }
 
 /**
+ * Context handler; Get groups from the page that initiated an Ajax request.
+ */
+function og_context_handler_ajax_request() {
+  // Even though the requested group comes from untrusted URL parameters, it is
+  // not necessary to check that the user has access to the group in this
+  // function, since og_context_determine_context() does that before allowing
+  // the group to be used.
+  if (!empty($_GET['og_ajax_context__group_type']) && !empty($_GET['og_ajax_context__gid']) && og_is_group($_GET['og_ajax_context__group_type'], $_GET['og_ajax_context__gid'])) {
+    return array($_GET['og_ajax_context__group_type'] => array($_GET['og_ajax_context__gid']));
+  }
+}
+
+/**
  * Helper function to handle views page access.
  *
  * @param $group_type