diff --git a/src/applications/diffusion/controller/DiffusionCommitController.php b/src/applications/diffusion/controller/DiffusionCommitController.php
--- a/src/applications/diffusion/controller/DiffusionCommitController.php
+++ b/src/applications/diffusion/controller/DiffusionCommitController.php
@@ -46,6 +46,7 @@
       ->needCommitData(true)
       ->needAuditRequests(true)
       ->setLimit(100)
+      ->needIdentities(true)
       ->execute();
 
     $multiple_results = count($commits) > 1;
@@ -504,15 +505,13 @@
 
     $phids = $edge_query->getDestinationPHIDs(array($commit_phid));
 
-    if ($data->getCommitDetail('authorPHID')) {
-      $phids[] = $data->getCommitDetail('authorPHID');
-    }
+
     if ($data->getCommitDetail('reviewerPHID')) {
       $phids[] = $data->getCommitDetail('reviewerPHID');
     }
-    if ($data->getCommitDetail('committerPHID')) {
-      $phids[] = $data->getCommitDetail('committerPHID');
-    }
+
+    $phids[] = $commit->getCommitterDisplayPHID();
+    $phids[] = $commit->getAuthorDisplayPHID();
 
     // NOTE: We should never normally have more than a single push log, but
     // it can occur naturally if a commit is pushed, then the branch it was
@@ -573,24 +572,11 @@
       }
     }
 
-    $author_phid = $data->getCommitDetail('authorPHID');
-    $author_name = $data->getAuthorName();
     $author_epoch = $data->getCommitDetail('authorEpoch');
 
     $committed_info = id(new PHUIStatusItemView())
-      ->setNote(phabricator_datetime($commit->getEpoch(), $viewer));
-
-    $committer_phid = $data->getCommitDetail('committerPHID');
-    $committer_name = $data->getCommitDetail('committer');
-    if ($committer_phid) {
-      $committed_info->setTarget($handles[$committer_phid]->renderLink());
-    } else if (strlen($committer_name)) {
-      $committed_info->setTarget($committer_name);
-    } else if ($author_phid) {
-      $committed_info->setTarget($handles[$author_phid]->renderLink());
-    } else if (strlen($author_name)) {
-      $committed_info->setTarget($author_name);
-    }
+      ->setNote(phabricator_datetime($commit->getEpoch(), $viewer))
+      ->setTarget($commit->renderAnyCommitter($viewer, $handles));
 
     $committed_list = new PHUIStatusListView();
     $committed_list->addItem($committed_info);
@@ -716,7 +702,7 @@
       return null;
     }
 
-    $author_phid = $data->getCommitDetail('authorPHID');
+    $author_phid = $commit->getAuthorDisplayPHID();
     $author_name = $data->getAuthorName();
     $author_epoch = $data->getCommitDetail('authorEpoch');
     $date = null;
@@ -748,10 +734,8 @@
       ->setImage($image_uri)
       ->setImageHref($image_href)
       ->setContent($content);
-
   }
 
-
   private function buildComments(PhabricatorRepositoryCommit $commit) {
     $timeline = $this->buildTransactionTimeline(
       $commit,
diff --git a/src/applications/repository/storage/PhabricatorRepositoryCommit.php b/src/applications/repository/storage/PhabricatorRepositoryCommit.php
--- a/src/applications/repository/storage/PhabricatorRepositoryCommit.php
+++ b/src/applications/repository/storage/PhabricatorRepositoryCommit.php
@@ -439,6 +439,77 @@
     return $repository->formatCommitName($identifier, $local = true);
   }
 
+  /**
+   * Make a strong effort to find a way to render this commit's committer.
+   * This currently attempts to use @{PhabricatorRepositoryIdentity}, and
+   * falls back to examining the commit detail information. After we force
+   * the migration to using identities, update this method to remove the
+   * fallback. See T12164 for details.
+   */
+  public function renderAnyCommitter(PhabricatorUser $viewer, array $handles) {
+    $committer = $this->renderCommitter($viewer, $handles);
+    if ($committer) {
+      return $committer;
+    }
+
+    return $this->renderAuthor($viewer, $handles);
+  }
+
+  public function renderCommitter(PhabricatorUser $viewer, array $handles) {
+    $committer_phid = $this->getCommitterDisplayPHID();
+    if ($committer_phid) {
+      return $handles[$committer_phid]->renderLink();
+    }
+
+    $data = $this->getCommitData();
+    $committer_name = $data->getCommitDetail('committer');
+    if (strlen($committer_name)) {
+      return $committer_name;
+    }
+
+    return null;
+  }
+
+  public function renderAuthor(PhabricatorUser $viewer, array $handles) {
+    $author_phid = $this->getAuthorDisplayPHID();
+    if ($author_phid) {
+      return $handles[$author_phid]->renderLink();
+    }
+
+    $data = $this->getCommitData();
+    $author_name = $data->getAuthorName();
+    if (strlen($author_name)) {
+      return $author_name;
+    }
+
+    return null;
+  }
+
+  public function hasCommitterIdentity() {
+    return ($this->getCommitterIdentity() !== null);
+  }
+
+  public function hasAuthorIdentity() {
+    return ($this->getAuthorIdentity() !== null);
+  }
+
+  public function getCommitterDisplayPHID() {
+    if ($this->hasCommitterIdentity()) {
+      return $this->getCommitterIdentity()->getIdentityDisplayPHID();
+    }
+
+    $data = $this->getCommitData();
+    return $data->getCommitDetail('committerPHID');
+  }
+
+  public function getAuthorDisplayPHID() {
+    if ($this->hasAuthorIdentity()) {
+      return $this->getAuthorIdentity()->getIdentityDisplayPHID();
+    }
+
+    $data = $this->getCommitData();
+    return $data->getCommitDetail('authorPHID');
+  }
 
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */
 
diff --git a/src/applications/repository/storage/PhabricatorRepositoryIdentity.php b/src/applications/repository/storage/PhabricatorRepositoryIdentity.php
--- a/src/applications/repository/storage/PhabricatorRepositoryIdentity.php
+++ b/src/applications/repository/storage/PhabricatorRepositoryIdentity.php
@@ -78,6 +78,14 @@
     return ($this->currentEffectiveUserPHID != null);
   }
 
+  public function getIdentityDisplayPHID() {
+    if ($this->hasEffectiveUser()) {
+      return $this->getCurrentEffectiveUserPHID();
+    } else {
+      return $this->getPHID();
+    }
+  }
+
   public function save() {
     if ($this->manuallySetUserPHID) {
       $this->currentEffectiveUserPHID = $this->manuallySetUserPHID;