diff --git a/src/applications/maniphest/typeahead/ManiphestAssigneeDatasource.php b/src/applications/maniphest/typeahead/ManiphestAssigneeDatasource.php
--- a/src/applications/maniphest/typeahead/ManiphestAssigneeDatasource.php
+++ b/src/applications/maniphest/typeahead/ManiphestAssigneeDatasource.php
@@ -13,6 +13,7 @@
 
   public function getComponentDatasources() {
     return array(
+      new PhabricatorViewerDatasource(),
       new PhabricatorPeopleDatasource(),
       new PhabricatorPeopleNoOwnerDatasource(),
     );
diff --git a/src/applications/people/typeahead/PhabricatorViewerDatasource.php b/src/applications/people/typeahead/PhabricatorViewerDatasource.php
--- a/src/applications/people/typeahead/PhabricatorViewerDatasource.php
+++ b/src/applications/people/typeahead/PhabricatorViewerDatasource.php
@@ -3,6 +3,8 @@
 final class PhabricatorViewerDatasource
   extends PhabricatorTypeaheadDatasource {
 
+  const FUNCTION_TOKEN = 'viewer()';
+
   public function getBrowseTitle() {
     return pht('Browse Viewer');
   }
diff --git a/src/applications/project/trigger/PhabricatorProjectTriggerManiphestOwnerRule.php b/src/applications/project/trigger/PhabricatorProjectTriggerManiphestOwnerRule.php
--- a/src/applications/project/trigger/PhabricatorProjectTriggerManiphestOwnerRule.php
+++ b/src/applications/project/trigger/PhabricatorProjectTriggerManiphestOwnerRule.php
@@ -18,6 +18,9 @@
     if ($value === PhabricatorPeopleNoOwnerDatasource::FUNCTION_TOKEN) {
       $value = null;
     }
+    if ($value === PhabricatorViewerDatasource::FUNCTION_TOKEN) {
+      $value = $this->getViewer()->getPHID();
+    }
     return $value;
   }
 
@@ -35,7 +38,8 @@
       throw new Exception(
         pht(
           'Owner rule value is required. Specify a user to assign tasks '.
-          'to, or the token "none()" to unassign tasks.'));
+          'to, the token "viewer()" to assign to the user moving tasks, '.
+          'or the token "none()" to unassign tasks.'));
     }
 
     if (count($value) > 1) {
@@ -123,7 +127,13 @@
   }
 
   public function getRuleViewDescription($value) {
-    $value = $this->convertTokenizerValueToOwner($value);
+    if (head($value) === PhabricatorViewerDatasource::FUNCTION_TOKEN) {
+      // TODO: String concatenation breaks 18n because of grammatical case;
+      // full string is "Assign task to user moving the task".
+      $value = 'user moving the task';
+    } else {
+      $value = $this->convertTokenizerValueToOwner($value);
+    }
 
     if (!$value) {
       return pht('Unassign task.');