We have some models that are have a user as a foreign key. But with about 25000 users in our system, it\'s a bit daunting to find the one we need.
Is there a solutio
The simplest out-of-the-box solution is to add the field to your ModelAdmin's raw_id_fields -- then you'll get a pop-up window in which you can use the built-in searching/filtering and pagination control's to find and select the object you're after.
If you really want autocomplete, the other answers give a you reasonable starting point.