diff --git a/avatars/avatars.py b/avatars/avatars.py
index eaf58bc52..51f6605ac 100644
--- a/avatars/avatars.py
+++ b/avatars/avatars.py
@@ -65,6 +65,9 @@ class BaseAvatar(object):
   def get_data_for_org(self, org):
     return self.get_data(org.username, org.email, 'org')
 
+  def get_data_for_external_user(self, external_user):
+    return self.get_data(external_user.username, external_user.email, 'user')
+
   def get_data(self, name, email_or_id, kind='user'):
     """ Computes and returns the full data block for the avatar:
         {
diff --git a/data/model/user.py b/data/model/user.py
index b3d5513f9..a94bc4cb8 100644
--- a/data/model/user.py
+++ b/data/model/user.py
@@ -499,8 +499,7 @@ def get_matching_user_namespaces(namespace_prefix, username, limit=10):
 
   return _basequery.filter_to_repos_for_user(base_query, username).limit(limit)
 
-def get_matching_users(username_prefix, robot_namespace=None,
-                       organization=None):
+def get_matching_users(username_prefix, robot_namespace=None, organization=None, limit=20):
   user_search =  _basequery.prefix_search(User.username, username_prefix)
   direct_user_query = (user_search & (User.organization == False) & (User.robot == False))
 
@@ -516,23 +515,24 @@ def get_matching_users(username_prefix, robot_namespace=None,
 
   if organization:
     query = (query
-             .select(User.username, User.email, User.robot, fn.Sum(Team.id))
+             .select(User.id, User.username, User.email, User.robot, fn.Sum(Team.id))
              .join(TeamMember, JOIN_LEFT_OUTER)
              .join(Team, JOIN_LEFT_OUTER, on=((Team.id == TeamMember.team) &
                                               (Team.organization == organization))))
 
   class MatchingUserResult(object):
     def __init__(self, *args):
-      self.username = args[0]
-      self.email = args[1]
-      self.robot = args[2]
+      self.id = args[0]
+      self.username = args[1]
+      self.email = args[2]
+      self.robot = args[3]
 
       if organization:
         self.is_org_member = (args[3] != None)
       else:
         self.is_org_member = None
 
-  return (MatchingUserResult(*args) for args in query.tuples().limit(10))
+  return (MatchingUserResult(*args) for args in query.tuples().limit(limit))
 
 
 def verify_user(username_or_email, password):
@@ -749,3 +749,16 @@ def get_region_locations(user):
   """ Returns the locations defined as preferred storage for the given user. """
   query = UserRegion.select().join(ImageStorageLocation).where(UserRegion.user == user)
   return set([region.location.name for region in query])
+
+def get_federated_logins(user_ids, service_name):
+  """ Returns all federated logins for the given user ids under the given external service. """
+  if not user_ids:
+    return []
+
+  return (FederatedLogin
+          .select()
+          .join(User)
+          .switch(FederatedLogin)
+          .join(LoginService)
+          .where(FederatedLogin.user << user_ids,
+                 LoginService.name == service_name))
diff --git a/data/users/__init__.py b/data/users/__init__.py
index 0cebb1cae..6f61b28f8 100644
--- a/data/users/__init__.py
+++ b/data/users/__init__.py
@@ -139,6 +139,31 @@ class UserAuthentication(object):
 
     return data.get('password', encrypted)
 
+  @property
+  def federated_service(self):
+    """ Returns the name of the federated service for the auth system. If none, should return None.
+    """
+    return self.state.federated_service
+
+  def query_users(self, query, limit=20):
+    """ Performs a lookup against the user system for the specified query. The returned tuple
+        will be of the form (results, federated_login_id, err_msg). If the method is unsupported,
+        the results portion of the tuple will be None instead of empty list.
+
+        Note that this method can and will return results for users not yet found within the
+        database; it is the responsibility of the caller to call link_user if they need the
+        database row for the user system record.
+
+        Results will be in the form of objects's with username and email fields.
+    """
+    return self.state.query_users(query, limit)
+
+  def link_user(self, username_or_email):
+    """ Returns a tuple containing the database user record linked to the given username/email
+        and any error that occurred when trying to link the user.
+    """
+    return self.state.link_user(username_or_email)
+
   def confirm_existing_user(self, username, password):
     """ Verifies that the given password matches to the given DB username. Unlike
         verify_credentials, this call first translates the DB user via the FederatedLogin table
diff --git a/data/users/database.py b/data/users/database.py
index e8cb3faad..4edb0f442 100644
--- a/data/users/database.py
+++ b/data/users/database.py
@@ -1,6 +1,10 @@
 from data import model
 
 class DatabaseUsers(object):
+  @property
+  def federated_service(self):
+    return None
+
   def verify_credentials(self, username_or_email, password):
     """ Simply delegate to the model implementation. """
     result = model.user.verify_user(username_or_email, password)
@@ -16,3 +20,11 @@ class DatabaseUsers(object):
   def confirm_existing_user(self, username, password):
     return self.verify_credentials(username, password)
 
+  def link_user(self, username_or_email):
+    """ Never used since all users being added are already, by definition, in the database. """
+    return (None, 'Unsupported for this authentication system')
+
+  def query_users(self, query, limit):
+    """ No need to implement, as we already query for users directly in the database. """
+    return (None, '', '')
+
diff --git a/data/users/federated.py b/data/users/federated.py
index e70740917..7ba1f4a80 100644
--- a/data/users/federated.py
+++ b/data/users/federated.py
@@ -7,7 +7,7 @@ from util.validation import generate_valid_usernames
 
 logger = logging.getLogger(__name__)
 
-VerifiedCredentials = namedtuple('VerifiedCredentials', ['username', 'email'])
+UserInformation = namedtuple('UserInformation', ['username', 'email', 'id'])
 
 class FederatedUsers(object):
   """ Base class for all federated users systems. """
@@ -15,11 +15,26 @@ class FederatedUsers(object):
   def __init__(self, federated_service):
     self._federated_service = federated_service
 
+  @property
+  def federated_service(self):
+    return self._federated_service
+
+  def get_user(self, username_or_email):
+    """ Retrieves the user with the given username or email, returning a tuple containing
+        a UserInformation (if success) and the error message (on failure).
+    """
+    raise NotImplementedError
+
   def verify_credentials(self, username_or_email, password):
     """ Verifies the given credentials against the backing federated service, returning
-        a tuple containing a VerifiedCredentials (if success) and the error message (if failed). """
+        a tuple containing a UserInformation (on success) and the error message (on failure).
+    """
     raise NotImplementedError
 
+  def query_users(self, query, limit=20):
+    """ If implemented, get_user must be implemented as well. """
+    return (None, 'Not supported')
+
   def _get_federated_user(self, username, email):
     db_user = model.user.verify_federated_login(self._federated_service, username)
     if not db_user:
@@ -34,7 +49,8 @@ class FederatedUsers(object):
         return (None, 'Unable to pick a username. Please report this to your administrator.')
 
       db_user = model.user.create_federated_user(valid_username, email, self._federated_service,
-                                                 username, set_password_notification=False)
+                                                 username,
+                                                 set_password_notification=False)
     else:
       # Update the db attributes from the federated service.
       db_user.email = email
@@ -42,6 +58,13 @@ class FederatedUsers(object):
 
     return (db_user, None)
 
+  def link_user(self, username_or_email):
+    (credentials, err_msg) = self.get_user(username_or_email)
+    if credentials is None:
+      return (None, err_msg)
+
+    return self._get_federated_user(credentials.username, credentials.email)
+
   def verify_and_link_user(self, username_or_email, password):
     """ Verifies the given credentials and, if valid, creates/links a database user to the
         associated federated service.
diff --git a/endpoints/api/search.py b/endpoints/api/search.py
index b11f1b53d..b5d233f3b 100644
--- a/endpoints/api/search.py
+++ b/endpoints/api/search.py
@@ -1,14 +1,15 @@
 """ Conduct searches against all registry context. """
 
 from endpoints.api import (ApiResource, parse_args, query_param, truthy_bool, nickname, resource,
-                           require_scope, path_param)
+                           require_scope, path_param, internal_only, Unauthorized, InvalidRequest,
+                           show_if)
 from data import model
 from auth.permissions import (OrganizationMemberPermission, ReadRepositoryPermission,
                               UserAdminPermission, AdministerOrganizationPermission,
                               ReadRepositoryPermission)
 from auth.auth_context import get_authenticated_user
 from auth import scopes
-from app import avatar
+from app import avatar, authentication
 from operator import itemgetter
 from stringscore import liquidmetal
 from util.names import parse_robot_username
@@ -16,6 +17,32 @@ from util.names import parse_robot_username
 import anunidecode # Don't listen to pylint's lies. This import is required.
 import math
 
+@show_if(authentication.federated_service) # Only enabled for non-DB auth.
+@resource('/v1/entities/link/<username>')
+@internal_only
+class LinkExternalEntity(ApiResource):
+  """ Resource for linking external entities to internal users. """
+  @nickname('linkExternalUser')
+  def post(self, username):
+    # Only allowed if there is a logged in user.
+    if not get_authenticated_user():
+      raise Unauthorized()
+
+    # Try to link the user with the given *external* username, to an internal record.
+    (user, err_msg) = authentication.link_user(username)
+    if user is None:
+      raise InvalidRequest(err_msg, payload={'username': username})
+
+    return {
+      'entity': {
+        'name': user.username,
+        'kind': 'user',
+        'is_robot': False,
+        'avatar': avatar.get_data_for_user(user)
+      }
+    }
+
+
 @resource('/v1/entities/<prefix>')
 class EntitySearch(ApiResource):
   """ Resource for searching entities. """
@@ -69,7 +96,22 @@ class EntitySearch(ApiResource):
         if admin_permission.can():
           robot_namespace = namespace_name
 
-    users = model.user.get_matching_users(prefix, robot_namespace, organization)
+    # Lookup users in the database for the prefix query.
+    users = model.user.get_matching_users(prefix, robot_namespace, organization, limit=10)
+
+    # Lookup users via the user system for the prefix query. We'll filter out any users that
+    # already exist in the database.
+    external_users, federated_id, _ = authentication.query_users(prefix, limit=10)
+    filtered_external_users = []
+    if external_users and federated_id is not None:
+      users = list(users)
+      user_ids = [user.id for user in users]
+
+      # Filter the users if any are already found via the database. We do so by looking up all
+      # the found users in the federated user system.
+      federated_query = model.user.get_federated_logins(user_ids, federated_id)
+      found = {result.service_ident for result in federated_query}
+      filtered_external_users = [user for user in external_users if not user.username in found]
 
     def entity_team_view(team):
       result = {
@@ -93,11 +135,20 @@ class EntitySearch(ApiResource):
 
       return user_json
 
+    def external_view(user):
+      result = {
+        'name': user.username,
+        'kind': 'external',
+        'avatar': avatar.get_data_for_external_user(user)
+      }
+      return result
+
     team_data = [entity_team_view(team) for team in teams]
     user_data = [user_view(user) for user in users]
+    external_data = [external_view(user) for user in filtered_external_users]
 
     return {
-      'results': team_data + user_data + org_data
+      'results': team_data + user_data + org_data + external_data
     }
 
 
diff --git a/static/js/directives/ui/entity-search.js b/static/js/directives/ui/entity-search.js
index 4611a81ae..c0be63673 100644
--- a/static/js/directives/ui/entity-search.js
+++ b/static/js/directives/ui/entity-search.js
@@ -148,6 +148,18 @@ angular.module('quay').directive('entitySearch', function () {
       };
 
       $scope.setEntityInternal = function(entity, updateTypeahead) {
+        // If the entity is an external entity, convert it to a known user via an API call.
+        if (entity.kind == 'external') {
+          var params = {
+            'username': entity.name
+          };
+
+          ApiService.linkExternalUser(null, params).then(function(resp) {
+            $scope.setEntityInternal(resp['entity'], updateTypeahead);
+          }, ApiService.errorDisplay('Could not link external user'));
+          return;
+        }
+
         if (updateTypeahead) {
           $(input).typeahead('val', $scope.autoClear ? '' : entity.name);
         } else {
@@ -193,7 +205,7 @@ angular.module('quay').directive('entitySearch', function () {
                 var entity = data.results[i];
 
                 var found = 'user';
-                if (entity.kind == 'user') {
+                if (entity.kind == 'user' || entity.kind == 'external') {
                   found = entity.is_robot ? 'robot' : 'user';
                 } else if (entity.kind == 'team') {
                   found = 'team';
@@ -276,6 +288,8 @@ angular.module('quay').directive('entitySearch', function () {
               template = '<div class="entity-mini-listing">';
               if (datum.entity.kind == 'user' && !datum.entity.is_robot) {
                 template += '<i class="fa fa-user fa-lg"></i>';
+              } else if (datum.entity.kind == 'external') {
+                template += '<i class="fa fa-user fa-lg"></i>';
               } else if (datum.entity.kind == 'user' && datum.entity.is_robot) {
                 template += '<i class="fa ci-robot fa-lg"></i>';
               } else if (datum.entity.kind == 'team') {
diff --git a/test/data/test.db b/test/data/test.db
index 433d9e949..522cb90c5 100644
Binary files a/test/data/test.db and b/test/data/test.db differ