Paris Hilton -- I'm a DJ Now!

She's been a sex tape star ... a singer ... a designer ... a TV star ... and now Paris Hilton is a frickin' DJ.

Paris hit the wheels of steel during a concert in Brazil ... and debuted a new song she's been working on with DJ AfroJack ... one of the best DJs on the planet.

But before she played the song, she sucked right up to the crowd ... telling them "I've partied all around the world ... to the best parties ... but I've never seen anyone party like you guys do in Brazil."

Hilton also said she and AfroJack are releasing an album soon.

Not everyone's a fan of DJ Paris ... after Deadmau5 caught wind, he posted a tweet saying, "It's over."