diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -1314,6 +1314,7 @@
     'ManiphestTaskPHIDType' => 'applications/maniphest/phid/ManiphestTaskPHIDType.php',
     'ManiphestTaskPriority' => 'applications/maniphest/constants/ManiphestTaskPriority.php',
     'ManiphestTaskPriorityDatasource' => 'applications/maniphest/typeahead/ManiphestTaskPriorityDatasource.php',
+    'ManiphestTaskPriorityHeraldAction' => 'applications/maniphest/herald/ManiphestTaskPriorityHeraldAction.php',
     'ManiphestTaskPriorityHeraldField' => 'applications/maniphest/herald/ManiphestTaskPriorityHeraldField.php',
     'ManiphestTaskQuery' => 'applications/maniphest/query/ManiphestTaskQuery.php',
     'ManiphestTaskResultListView' => 'applications/maniphest/view/ManiphestTaskResultListView.php',
@@ -5307,6 +5308,7 @@
     'ManiphestTaskPHIDType' => 'PhabricatorPHIDType',
     'ManiphestTaskPriority' => 'ManiphestConstants',
     'ManiphestTaskPriorityDatasource' => 'PhabricatorTypeaheadDatasource',
+    'ManiphestTaskPriorityHeraldAction' => 'HeraldAction',
     'ManiphestTaskPriorityHeraldField' => 'ManiphestTaskHeraldField',
     'ManiphestTaskQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
     'ManiphestTaskResultListView' => 'ManiphestView',
diff --git a/src/applications/maniphest/herald/ManiphestTaskPriorityHeraldAction.php b/src/applications/maniphest/herald/ManiphestTaskPriorityHeraldAction.php
new file mode 100644
--- /dev/null
+++ b/src/applications/maniphest/herald/ManiphestTaskPriorityHeraldAction.php
@@ -0,0 +1,87 @@
+<?php
+
+final class ManiphestTaskPriorityHeraldAction
+  extends HeraldAction {
+
+  const ACTIONCONST = 'maniphest.priority';
+  const DO_PRIORITY = 'do.priority';
+
+  public function supportsObject($object) {
+    return ($object instanceof ManiphestTask);
+  }
+
+  public function getActionGroupKey() {
+    return HeraldApplicationActionGroup::ACTIONGROUPKEY;
+  }
+
+  public function getHeraldActionName() {
+    return pht('Change priority to');
+  }
+
+  public function supportsRuleType($rule_type) {
+    return ($rule_type != HeraldRuleTypeConfig::RULE_TYPE_PERSONAL);
+  }
+
+  public function applyEffect($object, HeraldEffect $effect) {
+    $priority = head($effect->getTarget());
+
+    if (!$priority) {
+      $this->logEffect(self::DO_STANDARD_EMPTY);
+      return;
+    }
+
+    $adapter = $this->getAdapter();
+    $object = $adapter->getObject();
+    $current = $object->getPriority();
+
+    if ($current == $priority) {
+      $this->logEffect(self::DO_STANDARD_NO_EFFECT, $priority);
+      return;
+    }
+
+    $xaction = $adapter->newTransaction()
+      ->setTransactionType(ManiphestTransaction::TYPE_PRIORITY)
+      ->setNewValue($priority);
+
+    $adapter->queueTransaction($xaction);
+    $this->logEffect(self::DO_PRIORITY, $priority);
+  }
+
+  public function getHeraldActionStandardType() {
+    return self::STANDARD_PHID_LIST;
+  }
+
+  public function renderActionDescription($value) {
+    $priority = head($value);
+    $name = ManiphestTaskPriority::getTaskPriorityName($priority);
+    return pht('Change priority to: %s.', $name);
+  }
+
+  protected function getDatasource() {
+    return new ManiphestTaskPriorityDatasource();
+  }
+
+  protected function getDatasourceValueMap() {
+    return ManiphestTaskPriority::getTaskPriorityMap();
+  }
+
+  protected function getActionEffectMap() {
+    return array(
+      self::DO_PRIORITY => array(
+        'icon' => 'fa-pencil',
+        'color' => 'green',
+        'name' => pht('Changed Task Priority'),
+      ),
+    );
+  }
+
+  protected function renderActionEffectDescription($type, $data) {
+    switch ($type) {
+      case self::DO_PRIORITY:
+        return pht(
+          'Changed task priority to "%s".',
+          ManiphestTaskPriority::getTaskPriorityName($data));
+    }
+  }
+
+}