And he didn’t leave US politics behind for the evening – the star impersonated former US president Bill Clinton and appeared on stage as his House of Cards character Frank Underwood.
During the 11-minute opening number, he donned tap shoes and numerous costumes as he parodied the Broadway shows nominated for awards on Sunday night.
“I can’t believe how many people do that eight times a week,” a breathless Spacey said afterwards.
“But that’s why we’re gathered here to celebrate all the incredible work that you do. Now if someone will please find my cardiologist.”
His opening performance started with a parody of a song from hit musical Dear Evan Hansen. Spacey dressed as its title character, an anxious teenager – but he adapted the lyrics to reference his hosting concerns.
“Have you ever felt forgotten in the middle of going live on air? Have you ever felt the ratings could disappear?”
Spacey was named as Tony host after several other celebrities turned the job down.
Comedian Stephen Colbert joined Spacey on stage to riff on Groundhog Day, while former Tonys host Whoopi Goldberg was on hand to help him with his Come From Away parody.
He referenced speculation about her sexuality as he joked, “How long have you been in that closet, Whoopi?”
She replied: “Depends on who you ask, Kevin.”
He went on to make light of rumours about his own sexuality by dressing as Sunset Boulevard’s Norma Desmond.
“I’m coming out,” he sang in a black and gold dress, before adding: “Wait, no, wait.”
Spacey also poked fun at US presidential candidate Hilary Clinton during the ceremony.
Dressed as her husband Bill, Spacey referenced the plot of Dear Evan Hansen, which sees the teenager write fake emails to integrate himself into the family of a classmate who dies by suicide.
He addressed the musical’s star, saying: “Ben Platt was named one of Time magazine’s 100 Most Influential People. That’s very impressive. I was on that list a couple times, but, Ben, you know who you bumped off that list? My wife.
“Now, between you and me, you might be a better singer. But after seeing your show, there’s no doubt that Hillary is much better at creating fake email accounts than you.”
While in character, he also joked about recent US election result: “We’ve already had some surprising winners haven’t we? I’m not even talking about the Tony Awards.”
Dear Evan Hansen scooped the most Tony Awards of all the nominees, including Best New Musical.
It also took home Best Orchestration, Best Book of a Musical.
Platt fought off tough competition from stars in Groundhog Day and Falsettos to win Best Performance by an Actor in a Leading Role in a Musical.
Bette Midler took the equivalent award for actresses for her role in Hello, Dolly!
She gave a four-minute acceptance speech that forced organisers to play music over the top in an attempt to drive her off stage.
But the actress was having none of it, shouting to rapturous laughter: “Shut that crap off!”
Bette Midler won the Tony for the Best Leading Actress in a Musical for Hello, Dolly!
Rachel Bay Jones and Ben Platt pose with their Best Performance in a Musical awards for Dear Evan Hansen
Laurie Metcalf accepts the award for Best Performance by an Actress in a Leading Role in a Play for A Doll’s House, Part 2
Producer Stacey Mindich accepts Best Musical for Dear Evan Hansen
Rebecca Taichman poses with her award for Best Direction of a Play for Indecent
The cast of Dear Evan Hansen poses with their various awards
Ben Platt with his award for Best Performance by an Actor in a Leading Role in a Musical for Dear Evan Hansen
Cynthia Nixon accepts her Best Performance by an Actress in a Featured Role in a Play for Lillian Hellman’s The Little Foxes
Midler with her award for Best Performance by an Actress in a Leading Role in a Musical for Hello, Dolly!
Christopher Ashley won Best Direction of a Musical for Come From Away.
David Hyde Pierce, best known for his work on the TV show Frasier, performing Hello Dolly!
JT Rogers (left) accepts Best Play for Oslo
Kevin Kline won Best Leading Actor in a Play for Present Laughter
Gavin Creel accepts Best Performance by an Actor in a Featured Role in a Musical for Hello, Dolly!
James Earl Jones was presented with the Tony Lifetime Achievement
Hello, Dolly! also took home Best Revival of a Musical, and Best Performance by an Actor in a Featured Role in a Musical.
Best Play was won by Oslo, while a Tony went to August Wilson’s Jitney for Best Revival of a Play.