How She Got the Mother, of All Roles

For the record, Cristin Milioti is not engaged. “No, I swear to you I’m telling the truth!” she nearly shrieked upon hearing a morsel of Internet gossip. “My boyfriend’s going to get such a kick out of that.” She grinned conspiratorially. “But we’re very happy,” she said of the man in question, the furniture maker Jesse Hooker.

As an actor you know you’ve made it when the speculation begins. And Ms. Milioti, 28, is generating a high-pitched buzz as she prepares to step out with brown boots, yellow umbrella and electric bass on Monday night as the Mother on CBS’s “How I Met Your Mother” — a reveal eight seasons in the making.

“I got really lucky this year,” she said, her enormous doe eyes winged in liner and her tiny body adorned in fitted black T-shirt, white high-tops and cutoffs ending a few inches above some “righteous tan lines.”

What a year it has been. While performing the hits of Marketa Irglova and Glen Hansard as the Girl in the Broadway musical “Once,” she channeled the 1980s as Leonardo DiCaprio’s wife in Martin Scorsese’s “Wolf of Wall Street,” coming out in November. And in March, a day after leaving “Once,” for which she received a Tony nomination, she began filming as the Mother, who was introduced in the final moments of last season’s finale.

In a recent interview the endearingly frank Ms. Milioti — a New Jersey native and Brooklyn resident who has played a Mafioso’s daughter on “The Sopranos” and a kittenish writer on “30 Rock,” and still has nightmares about her middle-school Eddie Munster phase — spoke with Kathryn Shattuck about her transition from the stage to the set. Here are excerpts from their conversation.

Q. So, how did you land the role of the Mother?

A. You know, it was a very roundabout way. There weren’t really auditions for it. There were, like, meetings. I met with [the show’s creators] Craig [Thomas] and Carter [Bays] over Skype, and I didn’t know what it was for. And then people started coming to see “Once.” It was so secretive that I was like, “O.K., I think I know what this is about.”

ImageCristin Milioti
Credit...Fred R. Conrad/The New York Times

I read that Neil Patrick Harris mistakenly congratulated you on the role while you were still testing. Had you met him at the Tonys?

Maybe we met, but I don’t think we did, because you rehearse all morning, then you go to your matinee, then you do hair and makeup, then you do the red carpet, then you sit for four hours. And you never really have a meal. I imagine it’s like getting married or something. People are handing you tequila shots and Champagne. Suffice it to say I don’t remember much of the evening.

The Mother is a bass player in a band. And in “Once” you played the piano and sang. How’d you come to have an arsenal of instruments?

For “Once,” I learned the piano, essentially. For this, I’m attempting to learn bass. I mean, don’t ask me to play in front of anyone anytime soon. And I’ve always sung — way longer than I’ve acted. I just, like, couldn’t get a musical to save my life.

Then you landed “Once.”

I actually played a different role at a workshop in the beginning, and the only instrument I played was the sticks. John [Tiffany, the show’s director] really pushed for me to play this other role. We have a shorthand that is very special to me. We also can stay up and watch Beyoncé videos all night. She’s my bomb.

Did Beyoncé ever see the show?

One night I came out of my dressing room and there were Secret Service guys everywhere. And I got so excited. “Oh my God, Beyoncé is finally here!” And then it was Joe Biden — which was awesome, and he is so lovely. But Beyoncé never came. You know who did come and I lost my mind? Liza Minnelli, and I just died. She came out afterward and was like, “Oh my God, your energy.” I went completely silent.

And now you’ve got a role in a Scorsese film.

It’s a very fun role and I’m unrecognizable. I have a huge perm, acrylic tips, I’m spray-tanned and have a thick Queens accent. It’s a big role. Or at least I think it is. I constantly live in fear that I will show up to see it and they will have replaced me with Don Cheadle.