The play won a local competition and was performed at the well-known Hampstead Theater, where Mr. Kaluuya would later write and perform as a teenager. But after that triumph at age 9, he dropped theater for soccer, later finding his way back through improvisation classes at the Anna Scher Theater, a neighborhood institution that offered inexpensive drop-in sessions.
“Being young, working class and black, everything you do is policed,” Mr. Kaluuya said. “If someone hits you and you hit back, you are aggressive. If you cry, you are weak. You are kind of always pretending to be something. But in those improv classes, there was no pressure to be anything except honest, and that made me happy.” Although he knew he had “caught the bug,” he didn’t have the confidence, he added, to express a desire to act.
“If you are from the estates, you don’t say that,” he said. “Actually, the biggest problem is that you don’t know it’s possible. You don’t have the vocabulary, conceptually, to articulate that wish.”
Seeing fellow students get parts on television shows, he began to attend auditions, and at 16 won a role in the BBC drama “Shoot the Messenger,” starring David Oyelowo. Then came “Skins,” the BBC’s controversial, long-running series about hard-partying teenagers.
Mr. Kaluuya didn’t just co-star in “Skins,” he was also part of the writing team for the first two seasons, even as he was writing plays for the Hampstead Theater’s youth program and completing his A-levels, the graduating examinations in the British school system. (Drama was one of his subjects; his former teacher has written that he was the most talented actor he has ever come across.)
Mr. Kaluuya wanted to go to drama school but couldn’t afford it. Instead he kept writing for “Skins,” and in 2008 got a part in a play, “Oxford Street,” at the Royal Court. “That was a breakthrough for me,” Mr. Kaluuya said. “I couldn’t get seen for theater because I had no training. But that play led to ‘Sucker Punch,’ which changed everything.”
For “Sucker Punch,” written by Roy Williams, Mr. Kaluuya played one of the two leads, both young boxers. “I’d always been overweight and out of shape, but for this I trained for months and lost three stone” or more than 40 pounds, he said. “I gave it my all.” He won rave reviews and several awards, and drew the attention of a number of industry figures, among them the director Steve McQueen, who cast Mr. Kaluuya in his coming movie “Widows.”
“I had noticed him on ‘Skins,’ and then saw ‘Sucker Punch,’” Mr. McQueen said in a telephone interview. “He did this monologue while jumping rope which was amazing, and I was kind of mesmerized. He has that gift you don’t see often, a presence even in his stillness. You feel what he is feeling, you see what he is seeing. When I was casting ‘Widows,’ I knew it was him.”
After “Sucker Punch,” Mr. Kaluuya was cast in, among other things, the television series “Black Mirror,” but he felt frustrated by the response from the British movie and theater industry. “I wasn’t trained, I was too big, they didn’t want black leads, I don’t know,” Mr. Kaluuya said, clearly exasperated even at the memory. “You end up thinking, it’s just a glass ceiling, isn’t it?” He decided to set his sights on the United States, found an American agent and won a part in the 2015 thriller “Sicario.”
Before shooting “Sicario,” he read the script of “Get Out,” sent to him by his agent. “I was like, how do I make this happen?” Mr. Kaluuya recounted. “I totally loved it. I knew it spoke to me and my friends. That rage at the end; I know that.” He thought for a moment. “I was fortunate that I had acting,” he said. “If you had that anger on the street and let it out, you get arrested. I get applause.”
As it turned out, Mr. Peele had seen Mr. Kaluuya in “Black Mirror,” in the episode “Fifteen Million Merits.” In an email, Mr. Peele wrote: “It’s a soul-crushing performance in which he brilliantly performs the full spectrum of emotions I needed for Chris. Through most of the episode he’s restrained and subdued, but by the end his passion explodes into a primal unhinged monologue that is a thing of beauty.”
Although Mr. Peele was initially hesitant about casting a British actor instead of an American (a decision subsequently criticized by Samuel L. Jackson), he said that Mr. Kaluuya convinced him over a Skype conversation. “He put to bed my fears of any cultural rift in regards to race relations,” Mr. Peele said. “He really GOT the script in ways many didn’t. The risk excited him, where it made other American actors nervous.”
After Mr. Kaluuya flew to Los Angeles and performed the hypnosis sequence as his audition, the rest, Mr. Peele wrote, was history.
Mr. Kaluuya sighed wearily when asked about the controversy over his casting. “It speaks to the fact you are still getting policed,” he said, adding: “Even in the positive there is critique that a white person wouldn’t get.”
The success of “Get Out” hasn’t immediately led to other roles, he said, although he is thinking about a script he likes. Meanwhile, he isn’t exactly idle; he is writing a television series, as well as a film that he workshopped at the Sundance Screenwriters Lab, and has two movies (“Widows” and the Marvel “Black Panther”) due in 2018.
“It’s still a hustle!” he said cheerfully. “You crack on.”