George Santos is defending J.D. Vance as he faces allegations of dressing up like a woman when he was in law school ... George says one thing is clear, it's definitely NOT drag.

The ousted GOP congressman tells TMZ ... the images allegedly showing Donald Trump's running mate wearing a blonde wig and a skirt come across as more cross-dresser than drag queen.

George, of course, has dealt with a similar scandal himself ... when a former friend in Brazil posted an old photo from his days as a drag performer.

Difference is ... George says he was a full-on drag queen as a teenager ... and the Vance photos look more like a silly costume from a college house party.

The way George sees it ... if these photos show a drag queen, then the fellas on "RuPaul's Drag Race" are bona fide women.

Vance has not commented on the photos ... and George isn't sure that's the best political strategy in this case.

George's advice for Vance ... own this and go after the Political Left for trying to shame him and frame him as a drag queen, at a time when the Left is fighting for legal protections for drag queens.

George is uniquely qualified for this topic ... and he tells us why Vance doesn't need to worry about Trump here.