Is there a built-in login template in Django?

Yes. You can read all about it here: https://docs.djangoproject.com/en/1.8/topics/auth/default/#django.contrib.auth.decorators.login_required ... but here are some bullet points:

• add 'django.contrib.auth.middleware.AuthenticationMiddleware' to MIDDLEWARE_CLASSES in settings.py
• add 'django.contrib.auth' and 'django.contrib.contenttypes' to INSTALLED_APPS in settings.py
• setup a URL for the login using django.contrib.auth.views.login for the view, such as url(r'^login/$', 'django.contrib.auth.views.login',name="my_login")
• In your view, include the login_required decorator and add it before your view. For example...

views.py...

from django.contrib.auth.decorators import login_required@login_requireddef home(request):  return HttpResponse('Home Page')

By default, you then put the template inside my_template_directory/registration/login.html . Further info about that template can be found at the link in the beginning of this post.

As mentioned in the comments by the author, the easiest way to do this is to add the following lines to urls.py:

from django.contrib.auth.views import login, logouturlpatterns = patterns('',    url(r'^accounts/login/$', login, {'template_name': 'admin/login.html'}),    url(r'^accounts/logout/$', logout),)

As far as I know, adding the r'^accounts/$' and r'^accounts/profile/$' URLs is not necessary unless user profile management is required.

As suggested by @mmatt in comments, set LOGIN_REDIRECT_URL = '/' in settings.py to avoid the default redirect to /accounts/profile/ after login. See LOGIN_REDIRECT_URL in Django settings documentation.

This should also still work in Django 2.x using path instead of url appropriately.

The most upvoted response by @brant is technically incorrect. Django provides default views to handle login functionality but per the documentation does not provide a template:

Django provides no default template for the authentication views. You should create your own templates for the views you want to use. The template context is documented in each view, see All authentication views.