Conor McGregor showed up in public for the first time since his big UFC 303 comeback fight was called off over an undisclosed injury -- and the UFC superstar looked no worse for wear.

35-year-old McGregor attended a movie premiere at his bar, The Black Forge Inn, in Dublin on Tuesday where they screened actor John Connors' new film, "The Black Guelph."

While most in attendance watched (and dug) the flick, all eyes were on McGregor ... who emerged (in public) for the first time since his UFC comeback fight against Michael Chandler was canceled via a Dana White announcement on Thursday.

The reason for the postponement?? An unspecified injury.

Whatever's hurt, it's not readily visible looking at McGregor ... who appeared to be in peak physical condition in footage posted to TikTok by user @el.paco246 from Darndale. No casts. No limp. Nothing.

The images also fully put to rest any speculation Notorious was in rehab -- as was suggested by Chael Sonnen this week (Conor's rep adamantly denied the rumor to TMZ Sports on Tuesday) -- 'cause not only was McGregor in a bar, he was seen drinking whiskey and beer.

It's unclear if the fight with Chandler will be rescheduled ... though both sides claim they want to settle the score in the Octagon.

Until that day comes, it's clear McGregor's longtime partner, Dee Devlin, is happy to get some QT with her man.

DD posted a photo of the couple in their Bentley as they headed to Black Forge, writing "Date night 😍❤️"

On the other side, Chandler -- who has been pursuing a McGregor fight for years -- doesn't appear to be taking the news as well as his foe from Ireland.

Iron Mike posted video on Tuesday addressing fans during a backwoods hike ... and openly admitting he doesn't know whether the OG 303 main event will ever take place.