ModelAdmin sorting?
formfield_for_manytomany
class SongInline(admin.TabularInline): model = Song extra = 0 def formfield_for_manytomany(self, db_field, request, **kwargs): if db_field.name == "soloists": kwargs["queryset"] = Singer.objects.order_by('last_name') return super(SongInline, self).formfield_for_manytomany(db_field, request, **kwargs)That answers your specific question of "ModelAdmin Ordering" but in your case, you can simply define a default ordering for your m2m model via the model ordering model meta class option.
http://docs.djangoproject.com/en/dev/ref/models/options/#ordering
class Singer(models.Model): # my model class Meta: ordering = ['name'] # your select box will respect this as well.