Casey Anthony is just another Buckeyes fan as far as Ohio State is concerned -- because the university ain't surprised one bit that the most hated woman in America is rocking their swag.

A rep for the university tells TMZ, "We are never surprised to see Buckeye pride displayed across the world. Buckeye hoodies and hats have traditionally been spotted across the world, and we understand that as a result, our logo will be seen in a wide range of news situations, whether positive or negative."

TMZ broke the story ... Casey was spotted out in Ohio this weekend -- the FIRST time since she was released from jail last month -- and she was decked out in an OSU cap.