The 36-year-old Sin City and Hart of Dixie actress is a member of the 26-year-old pop star's "squad" of besties. King recently expressed support for Swift on Twitter after Kanye West unveiled a song at his Yeezy Season 3 fashion show that appears to diss the singer.
In fact, she is so close to Swift that she made her the godmother of her second child, son Leo, who is about six months old.
King told E! News exclusively Friday the singer is "consistently active" with the baby boy, adding, "she's the best friend, godmother, human being that a person could ask to be in your orbit and I am very, very grateful for her."
She made her comments at the Kate Spade New York presentation at The Rainbow Room in New York during New York Fashion Week.
In addition to King, other members of Swift's squad include Gigi Hadid, 20, Hailee Steinfeld, 19, and Karlie Kloss, 23, all of whom starred in her "Bad Blood" music video last year. Many people view the group as an elite clique—and many of them wish they could join it.
"I don't really believe in the word 'squad' as something that's, like, inclusive, this idea that…'You can't sit with us' type of thing," King told E! News, quoting the movie Mean Girls. "The idea of a squad is really the idea of friendship and the idea that everybody's welcome, the idea that women should be supporting other women and that's something that's really important...everyone knows I'm quite the feminist and I really believe that."
"I think that women, unfortunately, can be the greatest perpetrators on each other," she said, adding that they "shame each other more than men do."
"That's something that I'd like to see changed in the world," King said.