The Irish superstar claims he IS fighting Dustin Poirier on January 23 ... and he says he wants the mega event to go down at AT&T Stadium in Dallas.

The Notorious made the announcement on Twitter, writing ... "I accept, Jan 23rd is on!"

McGregor continued ... "My goal is to see this fight take place in Cowboy stadium. Proper Style! Jerry Jones is a friend and the stadium can hold our crowd. I will be ready for Texas and Texas will be ready for my fans!"

FYI, the UFC has not confirmed the news.

Remember, last week Conor expressed interest in fighting the 31-year-old, #2 ranked UFC Lightweight ... but with 1 very important caveat.

The fight had to be in 2020 ... which presented a problem 'cause it's already mid-October and most of the UFC's cards are already set.

Our UFC sources told us Dana White was willing to make the fight ... but it'd have to go down in January -- and it seems that's exactly what's going to happen.

Conor and Dustin have history ... the 2 men fought at UFC 178 in 2014. McGregor knocked out Poirier in the 1st round.

But, Dustin isn't the only guy Conor wants to put his hands on ... 'cause The Notorious says after Poirier, "Then Manny [Pacquiao]"