Zoe Saldana has come back to Earth.

After a string of intergalactic movies, the “Avatar” and “Star Trek Beyond” actress finds her feet firmly planted in Tampa, Florida, in Ben Affleck’s prohibition-era crime thriller “Live By Night” (in cinemas Friday), where she plays a Cuban rum importer named Graciela.

It took some coaxing, Saldana, 38, told us in a recent chat. “My husband was very encouraging and was not going to let me self-sabotage and not play this role,” she says of artist Marco Perego, explaining she almost turned the role down. “Then I realized that it was because I didn’t have enough belief in myself.”

She blames the universe for the spate of self-doubt — literally. “I’d been in the last ten years playing primarily characters that are set in the future and that live outside of Earth,” she says. “For ten years I’ve been adjusting my physicality more than my mind, I guess, into a character. I stopped kind of challenging myself.”

Her co-star and director, Affleck, also gave her the boost she needed. “Ben was so encouraging and so empowering. He was like, ‘You have to do this. You have to believe in yourself.’”

During our chat, Saldana also opened up about her family — excitedly relaying life with her identical twin sons Cy and Bowie, who recently turned 2 and often star on her Instagram page. “Oh my god, I’m having so much fun planning birthdays for little kids,” she says. “It’s so much fun. It’s better than planning birthdays for adults.” The latest was clown themed, as a nod to the Fellini movies Italian-born Perego has been showing the kids.

While L.A.-based Saldana missed the New York premiere of “Live By Night,” the city is a place close to her heart — she spent a chunk of her childhood growing up in Jackson Heights. “I will be a New Yorker until I die,” she says, describing how the city shaped her: “It’s because of my upbringing in New York City that I’m able to go to any part of the world and embrace everything that I see. ... It’s one of the most progressive cities.”

One fond memory she recalls is of the building she grew up in. “I remember very early on I would count how many doors were in my building per floor.

“That would trickle a chain thinking process of like how many apartments, how many families from how many countries are they coming from. How many different reasons as to why we’re all here. ... I always remember feeling so grateful to know that New York was filled with so many people and that we were all just trying to keep our heads up and just keep moving forward, you know?”