How do I get Django Admin to delete files when I remove an object from the database/model?

You can receive the pre_delete or post_delete signal (see @toto_tico's comment below) and call the delete() method on the FileField object, thus (in models.py):

class MyModel(models.Model):
    file = models.FileField()
    ...

# Receive the pre_delete signal and delete the file associated with the model instance.
from django.db.models.signals import pre_delete
from django.dispatch.dispatcher import receiver

@receiver(pre_delete, sender=MyModel)
def mymodel_delete(sender, instance, **kwargs):
    # Pass false so FileField doesn't save the model.
    instance.file.delete(False)

Try django-cleanup

pip install django-cleanup

settings.py

INSTALLED_APPS = (
    ...
    'django_cleanup', # should go after your apps
)

Django 1.5 solution: I use post_delete for various reasons that are internal to my app.

from django.db.models.signals import post_delete
from django.dispatch import receiver

@receiver(post_delete, sender=Photo)
def photo_post_delete_handler(sender, **kwargs):
    photo = kwargs['instance']
    storage, path = photo.original_image.storage, photo.original_image.path
    storage.delete(path)

I stuck this at the bottom of the models.py file.

the original_image field is the ImageField in my Photo model.