Conor McGregor Supports Justin Timberlake After DWI Arrest, 'Free JT'

Justin Timberlake's got a UFC superstar ready to fight for his freedom ... with Conor McGregor throwing his support behind the singer following his DWI arrest.

Notorious reacted to the "Selfish" crooner's legal troubles roughly 24 hours after the news broke on Tuesday ... and he's certainly not turning his back on Timberlake over the matter.

"Free JT," McGregor said on Wednesday ... sharing a pic of the musician's mug shot for good measure.

Of course, there is a bit of irony in McGregor showing love for someone who just got out the slammer ... as his fans have had to do the same for him after his own run-ins with the law in the past.

McGregor isn't alone in backing JT -- the *NSYNC leader's attorney, Edward Burke Jr., told TMZ he is ready to "vigorously" defend his client against the allegations.

It's unclear how tight McGregor and Timberlake are ... but the former referred to the guy as his "brother" when they posed together at UFC 200 back in 2016.

Timberlake also proved he's quite the McGregor fan himself ... channeling the fighter's most famous quote in the middle of his concert earlier this year.