Это расширяет ответ Джеффруа:
from django.contrib.auth.forms import UserCreationForm
class UserForm(UserCreationForm):
class Meta:
model = User
def __init__(self, *args, **kwargs):
super(UserForm, self).__init__(*args, **kwargs)
self.fields['email'].required = True
self.fields['first_name'].required = True
self.fields['last_name'].required = True
ModelAdmin:
from django.contrib.auth.admin import UserAdmin
class CustomUserAdmin(UserAdmin):
add_form = UserForm
add_fieldsets = (
(None, {'fields':('username','password1','password2','first_name','last_name','email'),}),)
А затем отмените регистрацию, как указано выше:
admin.site.unregister(User)
admin.site.register(User, CustomUserAdmin)