Diddy Is 'Incredibly Proud' Of Twin Daughters New Streetwear Brand

Diddy's twin daughters Jessie and D'Lila are making moves while their father sits behind bars at Fort Dix ... 'cause TMZ has learned they're launching a new streetwear brand.

Jessie and D'Lila officially launched their fashion brand Tuesday ... it's called "12TWINTY1" ... and it's a unisex brand that is sure to start making waves immediately.

Diddy tells TMZ ... "I'm incredibly proud of Jessie and D'Lila. They've worked hard to build something that's authentically theirs, and watching them turn an idea into a real business has been inspiring."

He continues ... "This is about two talented young women with a vision, a strong work ethic, and the courage to put their creativity out into the world. I hope people judge 12TWINTY1 on the quality of what they've created, because they've earned that opportunity."

The sisters have been teasing their project for several weeks on social media ... but now it's officially online.

That said, we'll have to see where the girls go with it ... because, as you know, Jessie and D'Lila have been seen in great company as of late while their music mogul father does hard time.

These two 18-year-olds have mingled with the likes of Kim Kardashian, Kaia Gerber, and Kylie Jenner, each with their own brands that are at the top of the game.