The couple tied the knot on Saturday, February 16.
Criss proposed in January 2018, over seven years after he started dating Mia, and posted the happy news on Instagram.
"Mia and I have had seven and a half years of fun, wacky, wonderful, CRAZY adventures together," he wrote, "and I'm happy to announce that we're kicking those adventures up a notch. We're goin for it. To boldly go where neither of us have gone before. Engage."
He later told Us Weekly, "It's (been) a long time coming and I'm excited for the next chapter."
Swier accompanied her man to the Golden Globes at the Beverly Hilton Hotel in January, when he picked up the Best Performance by an Actor in a Limited Series or Motion Picture Made for Television honour for his portrayal of killer Andrew Cunanan in "The Assassination of Gianni Versace: American Crime Story". The big win put the actor into the history books as the first Filipino-American to win the award.
He also picked up a gong for the role at the Screen Actor's Guild Awards.
Criss now has to make plans for another big celebrity wedding - his former "Glee" castmate Lea Michele has asked him to sing at her upcoming nuptials.
She revealed she has had a firm confirmation from Darren and she recently told Brides magazine she hopes he will come as the wedding singer.
"He better perform," Lea says. "I'm performing at his wedding! Darren and I are such great friends. He's like a brother to me, so the fact that we’re in this really sort of important moment in our lives at the same time is really special."