diff --git a/database/migrations/structure/20230409_0101_username.sql b/database/migrations/structure/20230409_0101_username.sql
new file mode 100644
index 0000000..adfcb72
--- /dev/null
+++ b/database/migrations/structure/20230409_0101_username.sql
@@ -0,0 +1,3 @@
+ALTER TABLE `users`
+ADD `username` varchar(100) DEFAULT NULL,
+ADD UNIQUE `username` (`username`);
diff --git a/src/Cli/AddUserCommand.php b/src/Cli/AddUserCommand.php
index 27a0d0b..980cb79 100644
--- a/src/Cli/AddUserCommand.php
+++ b/src/Cli/AddUserCommand.php
@@ -21,6 +21,11 @@ class AddUserCommand extends Command
 
     public function execute(InputInterface $input, OutputInterface $output): int
     {
+        if (!filter_var($input->getArgument('email'), FILTER_VALIDATE_EMAIL)) {
+            $output->writeln('<error>Please provide a valid email address.</error>');
+            return 1;
+        }
+
         $user = new User();
         $user->setEmail($input->getArgument('email'));
         $user->setPlainPassword($input->getArgument('password'));
diff --git a/src/Controller/LoginController.php b/src/Controller/LoginController.php
index 34baae4..7a83d8c 100644
--- a/src/Controller/LoginController.php
+++ b/src/Controller/LoginController.php
@@ -109,11 +109,11 @@ class LoginController
             return new JsonContent(['success' => true]);
         }
 
-        $user = $this->userRepository->getByEmail($this->request->post('email'));
+        $user = $this->userRepository->getByEmailOrUsername($this->request->post('email'));
         if ($user === null || !$user->checkPassword($this->request->post('password'))) {
             return new JsonContent([
                 'error' => [
-                    'errorText' => 'No user found with the given email address or the given password is wrong. You can <a href="/password/requestReset?email=' .
+                    'errorText' => 'No user found with the given email address / username or the given password is wrong. You can <a href="/password/requestReset?email=' .
                         urlencode($this->request->post('email')) . '" title="Request password reset">request password reset</a>!'
                 ]
             ]);
@@ -200,11 +200,11 @@ class LoginController
             }
         }
 
-        $user = $this->userRepository->getByEmail($this->request->post('email'));
+        $user = $this->userRepository->getByEmailOrUsername($this->request->post('email'));
         if ($user === null) {
             return new JsonContent([
                 'error' => [
-                    'errorText' => 'No user found with the given email address.'
+                    'errorText' => 'No user found with the given email address / username.'
                 ]
             ]);
         }
diff --git a/src/PersistentData/Model/User.php b/src/PersistentData/Model/User.php
index 1a284d4..92c4495 100644
--- a/src/PersistentData/Model/User.php
+++ b/src/PersistentData/Model/User.php
@@ -8,12 +8,14 @@ class User extends Model implements IUser
 {
     protected static string $table = 'users';
 
-    protected static array $fields = ['email', 'password', 'type', 'google_sub', 'created'];
+    protected static array $fields = ['email', 'username', 'password', 'type', 'google_sub', 'created'];
 
     private static array $types = ['user', 'admin'];
 
     private string $email = '';
 
+    private ?string $username = null;
+
     private ?string $password = null;
 
     private string $type = 'user';
@@ -27,6 +29,11 @@ class User extends Model implements IUser
         $this->email = $email;
     }
 
+    public function setUsername(?string $username): void
+    {
+        $this->username = $username;
+    }
+
     public function setPassword(?string $hashedPassword): void
     {
         $this->password = $hashedPassword;
@@ -64,6 +71,11 @@ class User extends Model implements IUser
         return $this->email;
     }
 
+    public function getUsername(): ?string
+    {
+        return $this->username;
+    }
+
     public function getPassword(): ?string
     {
         return $this->password;
diff --git a/src/Repository/UserRepository.php b/src/Repository/UserRepository.php
index cc03b44..3882d9d 100644
--- a/src/Repository/UserRepository.php
+++ b/src/Repository/UserRepository.php
@@ -27,6 +27,23 @@ class UserRepository implements IUserRepository
         return $this->pdm->selectFromDb($select, User::class);
     }
 
+    public function getByUsername(string $username): ?User
+    {
+        $select = new Select(\Container::$dbConnection);
+        $select->where('username', '=', $username);
+
+        return $this->pdm->selectFromDb($select, User::class);
+    }
+
+    public function getByEmailOrUsername(string $emailOrUsername): ?User
+    {
+        if (filter_var($emailOrUsername, FILTER_VALIDATE_EMAIL)) {
+            return $this->getByEmail($emailOrUsername);
+        }
+
+        return $this->getByUsername($emailOrUsername);
+    }
+
     public function getByGoogleSub(string $sub): ?User
     {
         $select = new Select(\Container::$dbConnection);
diff --git a/views/account/account.php b/views/account/account.php
index 315c71b..6a26290 100644
--- a/views/account/account.php
+++ b/views/account/account.php
@@ -25,6 +25,7 @@
             <hr>
             <?php /* TODO: disabled for the time being, email modification should be implemented */ ?>
             <input type="email" class="text big fullWidth" name="email" placeholder="Email address" value="<?= $user['email'] ?>" disabled>
+            <input type="text" class="text big fullWidth marginTop" name="username" placeholder="Username" value="<?= $user['username'] ?>" disabled>
             <input type="password" class="text big fullWidth marginTop" name="password_new" placeholder="New password" minlength="6">
             <input type="password" class="text big fullWidth marginTop" name="password_new_confirm" placeholder="New password confirmation" minlength="6">
             <p id="accountFormError" class="formError justify marginTop"></p>
diff --git a/views/login/login.php b/views/login/login.php
index 6c3cc79..d8dabfb 100644
--- a/views/login/login.php
+++ b/views/login/login.php
@@ -4,7 +4,7 @@
     <h2>Login</h2>
     <div class="box">
         <form id="loginForm" action="/login" method="post" data-redirect-on-success="<?= $redirectUrl ?>">
-            <input type="email" class="text big fullWidth" name="email" placeholder="Email address" required autofocus>
+            <input type="text" class="text big fullWidth" name="email" placeholder="Email address / Username" required autofocus>
             <input type="password"  class="text big fullWidth marginTop" name="password" placeholder="Password" required minlength="6">
             <p id="loginFormError" class="formError justify marginTop"></p>
             <div class="right marginTop">