CM Punk Returning to Octagon at UFC 225

CM Punk is finally returning to the Octagon, TMZ Sports has confirmed -- and this time, he vows to make up for that loss against Mickey Gall.

Punk was clapping back at trolls on Twitter when he broke the news ... responding to someone who asked, "When are we gonna see you cry again in the octagon?"

Punk's response ... "June nine, after I win and lock eyes with my beautiful wife, embrace my coaches and shout out my entire team."

June 9 is UFC 225 in Chicago -- Punk's hometown. For now, there's no word on who his opponent will be.

Punk hasn't fought since UFC 203 back in Sept. 2016 when he suffered a brutal submission loss in the 1st round to Gall.