Kyrie Irving -- I'm In the Underwear Biz ... Trust Me With Your Junk!

Cleveland Cavs star Kyrie Irving wants to get into your pants ... as the latest NBA star to launch his own mens underwear line ... TMZ Sports has learned.

We're told Irving has struck a deal with the PSD underwear brand -- which already has endorsement deals in place with NFL stars like Marshawn Lynch and Stevie Johnson.

According to PSD, Irving will "work directly with PSD’s designers developing his own underwear line, becoming the face of PSD for the foreseeable future."

Irving is hoping to launch his undie line later this year.

Underwear is the hot trend with jocks lately -- with everyone from Cristiano Ronaldo to Kevin Durant and Russell Westbrook getting in the game.