Janet McTeer is one of those actors you’re always happy to see listed in the cast list of anything. The sight of her name means that no matter how good/bad/indifferent the rest of the movie, TV show or play turns out to be, the bits that feature her will be terrific, so there’s something to look forward to.

McTeer has, of course, headlined many projects, particularly in theater; among other accolades, she won pretty much every award a person can win for her portrayal of Nora in “A Doll’s House,” which originated in London in 1996 before moving to Broadway the following year.

But I do not get to London theater very often, so I was not aware of her wide-ranging fabulousness until, as a baby TV critic, I reviewed “The Amazing Mrs. Pritchard,” an underwhelming PBS miniseries saved only by the artistic strength of its cast.

The first time I saw McTeer enter, as some highly formidable British politician or other, I thought, “Who is this woman?” I was shocked to find that the answer included “the star of ‘Tumbleweeds,’?” which I had absolutely believed starred an American actress. That’s how good the accent was.

Since then, I have continued to miss her on stage, in productions of “Mary Stuart,” “God of Carnage,” “Les Liasons Dangereuses” and “Bernhardt/Hamlet.” I thrilled to her performances in film — please watch “Albert Nobbs” if you haven’t already — but my main source sustenance has come from television. “Into the Storm,” “Five Days,” “Damages,” “The White Queen,” “Parade’s End,” “The Honorable Woman,” “Jessica Jones,” “I’m Sorry for Your Loss” and, most recently, “Ozark,” which dropped its third season on Netflix in March. If you still need a reason to rejoice over the border-blowing explosion of American television, the increased availability of Janet McTeer performances should pretty much do it.

“In England, everyone goes from stage to film to television, and there’s no stigma at all,” she says. “When I got here, I realized that didn’t happen, at least not at first, but now it’s changed. It’s been said before, but now TV is filled with great writing. And that’s all I’ve ever cared about.”

McTeer, like much of the rest of the country, is holed up at home — in her case, in Maine. She had been filming on set in Baltimore for the upcoming Showtime series “The President Is Missing” when concerns over the coronavirus pandemic shut production down.

The third season of “Ozark” was finished long before the virus hit the U.S. Even now, McTeer considers herself “a working actor,” and she loves the show, which she says has been one of her best working experiences.

More important, to audiences anyway, Helen Pierce, the tough-as-nails cartel attorney she plays, has a bigger role this season. Although she went from guest to regular in

the second season, she

says, she was also appearing in “Sorry for Your Loss”; its cancellation freed her up a bit, to the benefit of “Ozark.”

Helen resumes her storyline in the most dramatic way possible — being waterboarded at the behest of her always ruthless and increasingly paranoid boss, crime lord Camino Del Rio (Esai Morales). And though she has done many things in her career, this is the first time McTeer has played a victim of torture.

“When they sent me the script, I laughed out loud,” she says. “Because it’s perfect. She’s the mean one, the super controlling one, and now she’s being controlled.”

McTeer and star Laura Linney shared a house along with a makeup artist, she says, “and it was great. We’re all in our 50s, with kids and families, and so we were all in the same boat.”

In fact, she prefers doing television and stage precisely because of that camaraderie. “I feel like it leads to better acting,” she says. “At least for me. I mean, some people can just show up and turn on for a day or two, and that’s great. But I’m a slow-burn actor, and I like to feel like I’m in a company.”

McTeer says she came to acting “relatively late, 16 or 17” and then only through a series of events that sound a bit like a play themselves.

In high school, the bus stop for both the boys’ and girls’ schools was outside the York Theatre Royal, and students would mingle in its cafe.

When McTeer needed a part-time job, it seemed only natural she would work in the cafe, where she met a bunch of actors who then let her in to see some of the plays.

She didn’t think she could be an actor — “I’m 6 feet tall, and I’ve never been what you would call conventionally pretty” — until she attended a performance of “She Stoops to Conquer”: “The lights went down, and this excitement just welled up, and I thought, ‘If I don’t have a go at this, I will regret it.’?”

When she told some of the actors she had become friends with at the Theatre Royal, they laughed.

“They nicely told me where I should apply, but their attitude was, ‘You’re this little 16-year-old. You don’t just suddenly decide you’re going to be an actor.’

“Two of them were Gary Oldman and Michael Simkins, and I’ve worked with them since.”

She was not ever, as she has said, an obvious choice for ingenue roles, and, in fact, she never played one. But that turned out to be less of a problem than she imagined. “I thought it would be harder than it was,” she says. “I didn’t get any of those tiny, pretty roles, but there are still tons of roles out there.”

For her, the best characters are the most extreme, or, at least, the most removed from her own self.

“I love doing period because it transports me,” she says. “When I do modern, I like to do the same thing — like Helen, who is very different from me. In ‘The President Is Missing,’ I play the White House chief of staff, which is amazing.”

The characters she plays often seep into her actual life as she plays them.

“Sometimes I’ll follow someone who walks the way I think a character should walk. With Helen, we talked a lot about compartmentalizing. ‘Ozark’ is about how people deal with their families: How do you deal with bringing this illegal thing into your family?”

And sometimes, she says, she just walks through the woods, talking the part through. “That’s what I’ll be doing now, I guess,” she says. “But I’m a worker. I work at it.”