Williams and Kail worked together in 2018 when she starred in the award-winning miniseries Fosse/Verdon, which Kail executive produced and directed several episodes of. The couple didn't get together right away, however. At the time, Williams was still married to musician Phil Elverum, and Kail was with his ex-wife Angela Christian.
After their respective relationships ended, Williams and Kail found their way to each other and had a whirlwind romance — welcoming a son together and getting engaged within a year. They have now been married since 2020 and are expecting their second child together. Their soon-to-be family of five also includes Williams' teenage daughter with the late Heath Ledger, Matilda Ledger.
While the Dawson's Creek actress and Hamilton director generally keep their relationship private, there have been some cute moments shared publicly over the years, whether they were appearing on a red carpet together or giving a shout-out in an awards show speech.
From co-workers to married parents, here's everything to know about Michelle Williams and Thomas Kail's relationship.
Fall 2018: Michelle Williams and Thomas Kail start working together on Fosse/Verdon
Williams and Kail first met when the FX series Fosse/Verdon began filming in the fall of 2018. In the miniseries, Williams stars as Tony Award-winning dancer Gwen Verdon opposite Sam Rockwell as the influential choreographer Bob Fosse. Kail was one of the executive producers of the series and directed 5 of the 8 episodes.
April 19, 2019: Michelle Williams splits from Phil Elverum
On April 19, 2019, a source told PEOPLE that Williams and her husband, Elverum, had split after less than a year of marriage. They got married in the summer of 2018 and news of the breakup came after Williams had been spotted in public without a wedding band.
"Michelle and Phil separated at the beginning of the year. It was an amicable split and they remain friends," a source said at the time.
December 30, 2019: Michelle Williams and Thomas Kail are engaged and expecting a baby
A little while after her split, Williams and Kail were spotted shopping for baby clothes at a maternity store in London, where Williams was filming Venom: Let There Be Carnage.
PEOPLE confirmed that same day that she and Kail were not only together, but engaged and expecting their first child together, confirming the pregnancy rumors that the baby clothes shopping spree sparked.
"Michelle fell in love," a source later told PEOPLE. "She is happy and fulfilled and ready for another child."
It was also revealed that Williams' daughter, Matilda, "played matchmaker" for the two.
A few days after their engagement news broke, Williams was spotted wearing an engagement ring as she arrived at JFK International Airport in New York City.
January 5, 2020: Michelle Williams and Thomas Kail attend the Golden Globes together
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Williams and Kail appeared on the red carpet together for the first time as a couple at the 2020 Golden Globe Awards. During the awards show, Williams was awarded best performance by an actress in a miniseries or television film for her role in Fosse/Verdon. She gave a powerful acceptance speech about a woman's right to choose and also urged women to vote "in your own self-interest." At the end of her speech, Williams gave her fiancé and daughter a shout-out. "Tommy and Matilda, I can't wait to come home to you," she said.
That same night, the ultra-private couple made a rare appearance on Instagram via a photo that Williams' longtime friend Busy Philipps posted. Philipps shared a photo of the three of them together at the Los Angeles restaurant Jon & Vinny's with Williams' Golden Globe sitting on the table. Kail was affectionately resting his head on his fiancée's shoulder and Williams placed her hand on his arm.
January 19, 2020: Michelle Williams and Thomas Kail make another awards show appearance
Not long after their debut at the Golden Globes, Williams and Kail walked another red carpet at the 2020 Screen Actors Guild Awards, where Williams took home the award for outstanding performance by a female actor in a television movie or miniseries.
In her acceptance speech, she mentioned Kail and said, "Tommy, like everything else in our life, I share this with you."
Williams also praised her daughter in the speech. "Matilda, it's one thing to be completely honest as an actor, it's another thing to be completely honest as a human being," she said. "And that's just who you are and how you live, and you teach me just by being you. I love you and I'm coming home."
March 2020: Thomas Kail is seen wearing a wedding band, prompting marriage rumors
In March 2020, Kail was seen wearing what looked like a wedding band while out with Williams, sparking rumors that the pair had secretly married.
June 2020: Michelle Williams and Thomas Kail welcome their first baby together
Williams and Kail welcomed their first child together in June 2020, making Kail a first-time father.
Two years after her son's birth, the actress revealed his name Hart, for the first time in a May 2022 interview with Variety.
"It was a reminder that life goes on," Williams told the publication about welcoming Hart during a pandemic. "The world we brought a baby into is not the world we thought we were bringing a baby into, but the baby is ignorant of that. He experiences the unmitigated joy of discovery and the happiness of a loving home."
May 10, 2022: Michelle Williams and Thomas Kail are expecting another baby
Pascal Le Segretain/Getty
During the same 2022 interview with Variety, Williams shared that she and Kail were expecting another child, their second together and Williams' third.
"It's totally joyous," she told the outlet. "As the years go on, you sort of wonder what they might hold for you or not hold for you. It's exciting to discover that something you want again and again, is available one more time. That good fortune is not lost on me or my family."
November 2022: Michelle Williams and Thomas Kail welcome their second baby
Reps for the couple, however, did not comment on the news.