And Larson is crediting that friendship -- which was sparked by another commonality, co-star Woody Harrelson -- for saving her life.
"That [group of friends] saved my life," Larson told Vanity Fair in her May cover story. "I was able to talk with them about everything that was going on in my life, and it was with people who had been through it before and are also hilarious. That support and acceptance was everything. I was home-schooled, so I didn’t have friends that had the same interests as me, and I found it to be absolutely incredible."
Larson said it was the relentless promoting of "Room" that made her feel particularly lonely.
"I was embarrassed to keep talking about myself," she said. "Emma wrote this beautiful e-mail out of nowhere, and then one day Jen sent me a text message after she saw 'Room,' and we started talking."
Larson told the mag her relationship with Lawrence grew exponentially last year when the two were in Montreal filming movies. Larson was filming "The Glass Castle" -- where she played the daughter of Rex Walls, played by real-life father figure Harrelson -- while Lawrence was working on "Mother!"
"We just had a blast together, going to get dinner every Saturday night," Larson said. "It gave us all a chance to connect."
Her relationship with Stone blossomed at the 2016 Oscars, where Larson took home the Academy Award for Best Actress. Before the ceremony, Larson said Stone gave her a book called "I Can Fly," a card wishing her luck and an elephant totem for her purse.
"It’s those little things," she said.
On Oscar night 2017, where Stone took home Best Actress for her work in "La La Land," Larson posted a photo of her and Stone hugging, captioning the shot, "You know what’s better than winning? Watching your friend win.”
Harrelson told Vanity Fair he introduced the "very tight-knit group" to each other to "keep them honest and keep their ego[s] in check."
"It’s hard in this business, especially at that age, to experience celebrity and all the perks and all the temptations of celebrity," he said. "It’s incredible how they’ve navigated fame and stayed the people they are."
Inez and Vinoodh for Vanity Fair