Years before Hannah Waddingham stole TV viewers’ hearts as Rebecca, the owner of AFC Richmond, on “Ted Lasso” or became a viral meme as Septa Unella, the shame nun in “Game of Thrones,” the 49-year-old actor was a leading lady on London’s West End and on Broadway.

In “Hannah Waddingham: Home for Christmas,” now streaming on Apple TV+, the actor brings those two worlds together, a symbol not only of her arrival as a bona fide star but of her roots in musical theater — she’s starred in productions of “Spamalot,” “Into the Woods’’ and “Kiss Me, Kate.” And it’s a way for her to prove that stage actors really can do it all.

“There’s no reason why that craft can’t move into a different medium,” she said. “It’s just a different tool in your bag. That’s what I wanted with a special.”

Waddingham’s voice soars onstage — the production was filmed live before an audience at the London Coliseum, the same place where she spent her childhood watching her mother, Melodie Kelly, perform as part of the English National Opera Chorus. Joining her throughout the special are familiar faces, including her castmates from “Ted Lasso” (Did you know Phil Dunster can carry a tune?), and musical guests like Sam Ryder, Luke Evans, Leslie Odom Jr. and the Fabulous Lounge Swingers.

Waddingham is not only the star of the show, but she wrote all of the off-stage skits — one features Juno Temple, and another Brett Goldstein, whom Waddingham joins in a Jacuzzi. She was also the executive producer, making decisions on budgets, wardrobe edits and how to make it snow in the coliseum. “We would all sit there and brainstorm together,” she said. “I wasn’t treated like the talent.”

It’s been a long road for Waddingham, who first balked at the idea when her manager approached her about hosting her own musical extravaganza. “I would say that I’ve reached that point in my career when I just think, ‘Now the things that I wanted to do in the first place are happening,’” she said.

This interview has been edited and condensed for clarity.

Q: Congratulations on your special! Tell me how this all came together.

A: My manager, Nick Todisco, and I discussed doing a Christmas special a couple of years ago. I said, “People don’t want to see that — this chick from London coming along and doing a quite American-style Christmas special.” I said if I was going to do it, I want it to be old school, where it’s like “Saturday Night Live” meets a combination of the Rat Pack, Carol Burnett and Mary Tyler Moore. And it has to be on a stage and lean into the fact that I’ve been a leading lady in musical theater, both in New York and in London, for 22 years of my life. The thing I’m most proud of, which I will shout from every rooftop, is that not one note of the whole special has been tweaked, fiddled with, nothing. It’s completely live.

Q: You look euphoric on the stage. Does that feel more natural to you?

A: Theater is what I grew up with. The whole reason I wanted it in the London Coliseum is because that’s all I’ve ever known: sitting in the (orchestra) stalls watching my mom. In the U.K. for a long time, you couldn’t get into TV, which is why I spoke about it in my Emmy speech. I use my platform to say that people in musical theater are not jack of all trades, master of none. They are masters of all of them, because they have to be.

Q: Did it take a lot of persuading to get some of the “Ted Lasso” crew on board?

A: Nigh on, they all said yes. It was meant to be like, let’s see who’s around, let’s have one or two people. It was the most reassuring, comforting thing to have all of AFC Richmond going, “We’re totally in.” Have you seen how much Brendan Hunt is enjoying himself?

Q: When he’s onstage —

A: He doesn’t close his mouth for the whole song! Brendan asked about doing a bit on the side of the stage. With Nick Mohammed, I said we would love it if you would kind of be my stooge, and then you’ve been nagging me so much that I get you hoisted up to the flies. Then he went, “Oh, and I should stay there for the rest of the show with my legs (dangling).” It was just incredible that they would (pitch in ideas) and go, “And then we could do this!”

Q: Tell me about some of those song choices and musical guests.

A: I didn’t want famous people for famous’ sake. I wanted people who mean something to me. Luke Evans and I have known each other since we were 20. Sam Ryder I think is just one of our greatest talents. “ Please Come Home for Christmas “ was on Leslie Odom Jr.’s album, and it made my head go dizzy. I thought, “I have to sing that with him.” Also, I said to my little girl, “You choose someone,” and before I even finished the sentence, she said “Leslie Odom Jr.!” She’s obsessed with “Hamilton.”

Q: Was it important for you that the special also be funny?

A: It was important to me and to Apple. The folks at Apple kept saying, “Let’s make sure that we’ve got some great fun scenes, let’s make sure there’s an offstage, onstage element to it.” When they asked who would be my perfect scene partners, that was a complete no-brainer. All three of them — Juno, Brett and Jason (Sudeikis) — were 100% in with no question, and each of them were (so collaborative), asking what we should do. We shot those as inserts in Los Angeles after the special (was filmed in London).