Jared Leto -- My New Movie Role Is a Total Drag!

Believe it or not, this isn't Kristen Stewart doing the walk of shame the morning after ... it's Jared Leto on the set of his new film in New Orleans on Thursday.

The 40-year-old 30 Seconds to Mars singer -- who is no stranger to guyliner -- is now rockin' a wig, full face, ripped pantyhose and ginormous pumps to play a cross-dresser in the "Dallas Buyers Club," the same flick Matthew McConaughey has whittled himself down to nothing for.

Pretty woman, he ain't.