It's the highest compliment someone can get (from the porn industry) -- a XXX parody ... and now, Ronda Rousey is the latest star who's getting the hardcore treatment ... TMZ Sports has learned.

Porn legend Joanna Angel -- star of such classics as "F**kenstein," "Grand Theft Anal 10" and "Rock & Roll in My Butthole 2" -- is directing the film ... which is currently in production.

We're told Angel is a huge fan of Rousey -- and figured the flick would be the ultimate homage to the UFC legend.

BTW, the role of "Ronda ArouseMe" will be played by Kleio Valentien -- who was nominated for an AVN Award this year for Best 3-Way for her scene in "Captain America XXX: An Axel Braun Parody."