diff --git a/libraries/src/Application/IdentityAware.php b/libraries/src/Application/IdentityAware.php
index 1fe220a0a0f44..7281b5833e348 100644
--- a/libraries/src/Application/IdentityAware.php
+++ b/libraries/src/Application/IdentityAware.php
@@ -11,6 +11,7 @@
 defined('JPATH_PLATFORM') or die;
 
 use Joomla\CMS\User\User;
+use Joomla\CMS\User\UserFactoryInterface;
 
 /**
  * Trait for application classes which are identity (user) aware
@@ -27,6 +28,14 @@ trait IdentityAware
 	 */
 	protected $identity;
 
+	/**
+	 * UserFactoryInterface
+	 *
+	 * @var    UserFactoryInterface
+	 * @since  4.0.0
+	 */
+	private $userFactory;
+
 	/**
 	 * Get the application identity.
 	 *
@@ -50,8 +59,22 @@ public function getIdentity()
 	 */
 	public function loadIdentity(User $identity = null)
 	{
-		$this->identity = $identity ?: User::getInstance();
+		$this->identity = $identity ?: $this->userFactory->loadUserById(0);
 
 		return $this;
 	}
+
+	/**
+	 * Set the user factory to use.
+	 *
+	 * @param   UserFactoryInterface  $userFactory  The user factory to use
+	 *
+	 * @return  void
+	 *
+	 * @since   4.0.0
+	 */
+	public function setUserFactory(UserFactoryInterface $userFactory)
+	{
+		$this->userFactory = $userFactory;
+	}
 }
diff --git a/libraries/src/Factory.php b/libraries/src/Factory.php
index 0f355629ea649..0ca96aa4c1ee5 100644
--- a/libraries/src/Factory.php
+++ b/libraries/src/Factory.php
@@ -300,11 +300,21 @@ public static function getDocument()
 	 *
 	 * @return  User object
 	 *
-	 * @see     User
-	 * @since   1.7.0
+	 * @see         User
+	 * @since       1.7.0
+	 * @deprecated  5.0  Load the user service from the dependency injection container or via $app->getIdentity()
 	 */
 	public static function getUser($id = null)
 	{
+		@trigger_error(
+			sprintf(
+				'%1$s() is deprecated. Load the user from the dependency injection container or via %2$s::getApplication()->getIdentity().',
+				__METHOD__,
+				__CLASS__
+			),
+			E_USER_DEPRECATED
+		);
+
 		$instance = self::getApplication()->getSession()->get('user');
 
 		if (is_null($id))
@@ -560,7 +570,8 @@ protected static function createContainer(): Container
 			->registerServiceProvider(new \Joomla\CMS\Service\Provider\Session)
 			->registerServiceProvider(new \Joomla\CMS\Service\Provider\Toolbar)
 			->registerServiceProvider(new \Joomla\CMS\Service\Provider\WebAssetRegistry)
-			->registerServiceProvider(new \Joomla\CMS\Service\Provider\ApiRouter);
+			->registerServiceProvider(new \Joomla\CMS\Service\Provider\ApiRouter)
+			->registerServiceProvider(new \Joomla\CMS\Service\Provider\User);
 
 		return $container;
 	}
diff --git a/libraries/src/Service/Provider/Application.php b/libraries/src/Service/Provider/Application.php
index 842b5dcec417e..b68d4cbe9880c 100644
--- a/libraries/src/Service/Provider/Application.php
+++ b/libraries/src/Service/Provider/Application.php
@@ -20,6 +20,7 @@
 use Joomla\CMS\Console\SessionGcCommand;
 use Joomla\CMS\Console\SessionMetadataGcCommand;
 use Joomla\CMS\Factory;
+use Joomla\CMS\User\UserFactoryInterface;
 use Joomla\Console\Application as BaseConsoleApplication;
 use Joomla\Console\Loader\LoaderInterface;
 use Joomla\DI\Container;
@@ -62,6 +63,7 @@ function (Container $container)
 					$app->setDispatcher($container->get(DispatcherInterface::class));
 					$app->setLogger($container->get(LoggerInterface::class));
 					$app->setSession($container->get(SessionInterface::class));
+					$app->setUserFactory($container->get(UserFactoryInterface::class));
 
 					return $app;
 				},
@@ -84,6 +86,7 @@ function (Container $container)
 					$app->setDispatcher($container->get(DispatcherInterface::class));
 					$app->setLogger($container->get(LoggerInterface::class));
 					$app->setSession($container->get(SessionInterface::class));
+					$app->setUserFactory($container->get(UserFactoryInterface::class));
 
 					return $app;
 				},
@@ -108,6 +111,7 @@ function (Container $container)
 					$app->setCommandLoader($container->get(LoaderInterface::class));
 					$app->setLogger($container->get(LoggerInterface::class));
 					$app->setSession($container->get(SessionInterface::class));
+					$app->setUserFactory($container->get(UserFactoryInterface::class));
 
 					return $app;
 				},
diff --git a/libraries/src/Service/Provider/User.php b/libraries/src/Service/Provider/User.php
new file mode 100644
index 0000000000000..c172a734a92d6
--- /dev/null
+++ b/libraries/src/Service/Provider/User.php
@@ -0,0 +1,48 @@
+<?php
+/**
+ * Joomla! Content Management System
+ *
+ * @copyright  Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
+ * @license    GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\CMS\Service\Provider;
+
+defined('JPATH_PLATFORM') or die;
+
+use Joomla\CMS\User\UserFactory;
+use Joomla\CMS\User\UserFactoryInterface;
+use Joomla\Database\DatabaseInterface;
+use Joomla\DI\Container;
+use Joomla\DI\ServiceProviderInterface;
+
+/**
+ * Service provider for the user dependency
+ *
+ * @since  4.0
+ */
+class User implements ServiceProviderInterface
+{
+	/**
+	 * Registers the service provider with a DI container.
+	 *
+	 * @param   Container  $container  The DI container.
+	 *
+	 * @return  void
+	 *
+	 * @since   4.0
+	 */
+	public function register(Container $container)
+	{
+		$container->alias('user.factory', UserFactoryInterface::class)
+			->alias(UserFactory::class, UserFactoryInterface::class)
+			->share(
+				UserFactoryInterface::class,
+				function (Container $container)
+				{
+					return new UserFactory($container->get(DatabaseInterface::class));
+				},
+				true
+			);
+	}
+}
diff --git a/libraries/src/User/User.php b/libraries/src/User/User.php
index 0d7ae5ac473ad..e4992ae99ddec 100644
--- a/libraries/src/User/User.php
+++ b/libraries/src/User/User.php
@@ -251,18 +251,24 @@ public function __construct($identifier = 0)
 	 *
 	 * @return  User  The User object.
 	 *
-	 * @since   1.7.0
+	 * @since       1.7.0
+	 * @deprecated  5.0  Load the user service from the dependency injection container or via $app->getIdentity()
 	 */
 	public static function getInstance($identifier = 0)
 	{
+		@trigger_error(
+			sprintf(
+				'%1$s() is deprecated. Load the user from the dependency injection container or via %2$s::getApplication()->getIdentity().',
+				__METHOD__,
+				__CLASS__
+			),
+			E_USER_DEPRECATED
+		);
+
 		// Find the user id
 		if (!is_numeric($identifier))
 		{
-			if (!$id = UserHelper::getUserId($identifier))
-			{
-				// If the $identifier doesn't match with any id, just return an empty User.
-				return new static;
-			}
+			return Factory::getContainer()->get(UserFactoryInterface::class)->loadUserByUsername($identifier);
 		}
 		else
 		{
@@ -273,13 +279,13 @@ public static function getInstance($identifier = 0)
 		// Note: don't cache this user because it'll have a new ID on save!
 		if ($id === 0)
 		{
-			return new static;
+			return Factory::getContainer()->get(UserFactoryInterface::class)->loadUserById($id);
 		}
 
 		// Check if the user ID is already cached.
 		if (empty(self::$instances[$id]))
 		{
-			self::$instances[$id] = new static($id);
+			self::$instances[$id] = Factory::getContainer()->get(UserFactoryInterface::class)->loadUserById($id);
 		}
 
 		return self::$instances[$id];
diff --git a/libraries/src/User/UserFactory.php b/libraries/src/User/UserFactory.php
new file mode 100644
index 0000000000000..6cb9014a3d880
--- /dev/null
+++ b/libraries/src/User/UserFactory.php
@@ -0,0 +1,74 @@
+<?php
+/**
+ * Joomla! Content Management System
+ *
+ * @copyright  Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
+ * @license    GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\CMS\User;
+
+defined('_JEXEC') or die;
+
+use Joomla\Database\DatabaseInterface;
+
+/**
+ * Default factory for creating User objects
+ *
+ * @since  __DEPLOY_VERSION__
+ */
+class UserFactory implements UserFactoryInterface
+{
+	/**
+	 * The database.
+	 *
+	 * @var  DatabaseInterface
+	 */
+	private $db;
+
+	/**
+	 * UserFactory constructor.
+	 *
+	 * @param   DatabaseInterface  $db  The database
+	 */
+	public function __construct(DatabaseInterface $db)
+	{
+		$this->db = $db;
+	}
+
+	/**
+	 * Method to get an instance of a user for the given id.
+	 *
+	 * @param   int  $id  The id
+	 *
+	 * @return  User
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function loadUserById(int $id): User
+	{
+		return new User($id);
+	}
+
+	/**
+	 * Method to get an instance of a user for the given username.
+	 *
+	 * @param   string  $username  The username
+	 *
+	 * @return  User
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function loadUserByUsername(string $username): User
+	{
+		// Initialise some variables
+		$query = $this->db->getQuery(true)
+			->select($this->db->quoteName('id'))
+			->from($this->db->quoteName('#__users'))
+			->where($this->db->quoteName('username') . ' = ' . $this->db->quote($username));
+		$query->setLimit(1, 0);
+		$this->db->setQuery($query);
+
+		return $this->loadUserById((int) $this->db->loadResult());
+	}
+}
diff --git a/libraries/src/User/UserFactoryInterface.php b/libraries/src/User/UserFactoryInterface.php
new file mode 100644
index 0000000000000..c06f1b1a8c993
--- /dev/null
+++ b/libraries/src/User/UserFactoryInterface.php
@@ -0,0 +1,41 @@
+<?php
+/**
+ * Joomla! Content Management System
+ *
+ * @copyright  Copyright (C) 2005 - 2018 Open Source Matters, Inc. All rights reserved.
+ * @license    GNU General Public License version 2 or later; see LICENSE.txt
+ */
+
+namespace Joomla\CMS\User;
+
+defined('_JEXEC') or die;
+
+/**
+ * Interface defining a factory which can create User objects
+ *
+ * @since  __DEPLOY_VERSION__
+ */
+interface UserFactoryInterface
+{
+	/**
+	 * Method to get an instance of a user for the given id.
+	 *
+	 * @param   int  $id  The id
+	 *
+	 * @return  User
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function loadUserById(int $id): User;
+
+	/**
+	 * Method to get an instance of a user for the given username.
+	 *
+	 * @param   string  $username  The username
+	 *
+	 * @return  User
+	 *
+	 * @since   __DEPLOY_VERSION__
+	 */
+	public function loadUserByUsername(string $username): User;
+}