diff --git a/data/model.py b/data/model.py
index 7b300bedc..15eab7576 100644
--- a/data/model.py
+++ b/data/model.py
@@ -439,9 +439,9 @@ def get_matching_users(username_prefix, robot_namespace=None,
   return (MatchingUserResult(*args) for args in query.tuples().limit(10))
 
 
-def verify_user(username, password):
+def verify_user(username_or_email, password):
   try:
-    fetched = User.get(User.username == username)
+    fetched = User.get((User.username == username_or_email) | (User.email == username_or_email))
   except User.DoesNotExist:
     return None
 
diff --git a/endpoints/api.py b/endpoints/api.py
index 530672d87..553ac77e1 100644
--- a/endpoints/api.py
+++ b/endpoints/api.py
@@ -312,12 +312,11 @@ def signin_user():
   return conduct_signin(username, password)
 
 
-def conduct_signin(username, password):
-  #TODO Allow email login
+def conduct_signin(username_or_email, password):
   needs_email_verification = False
   invalid_credentials = False
 
-  verified = model.verify_user(username, password)
+  verified = model.verify_user(username_or_email, password)
   if verified:
     if common_login(verified):
       return make_response('Success', 200)
diff --git a/static/directives/signin-form.html b/static/directives/signin-form.html
index cf982f08b..814955ce6 100644
--- a/static/directives/signin-form.html
+++ b/static/directives/signin-form.html
@@ -1,7 +1,7 @@
 <div class="signin-form-element">
   <form class="form-signin" ng-submit="signin();">
     <input type="text" class="form-control input-lg" name="username"
-           placeholder="Username" ng-model="user.username" autofocus>
+           placeholder="Username or E-mail Address" ng-model="user.username" autofocus>
     <input type="password" class="form-control input-lg" name="password"
            placeholder="Password" ng-model="user.password">
     <button class="btn btn-lg btn-primary btn-block" type="submit">Sign In</button>