sortedm2m-filter-horizontal-widget is an admin widget for Gregor Mülleggers excellent django-sortedm2m library.

This allows for a familiar filter horizontal widget.

pip install django-sortedm2m-filter-horizontal-widget

Add sortedm2m_filter_horizontal_widget to your INSTALLED_APPS. (needed for static files)

In your ModelAdmin add the following function to override the default widget.

from sortedm2m_filter_horizontal_widget.forms import SortedFilteredSelectMultiple

class MyModelAdmin(admin.ModelAdmin):
    # ...

    def formfield_for_manytomany(self, db_field, request=None, **kwargs):
        if db_field.name == 'your_sortedm2m_field_name':
            kwargs['widget'] = SortedFilteredSelectMultiple()
        return super(MyModelAdmin, self).formfield_for_manytomany(db_field, request, **kwargs)

• Automatically assign widget if field is specified in ModelAdmin's filter_horizontal.
• Add tests