Idris was born in Peckham, South-East London, and is of Nigerian descent. He is the youngest of six children raised by a single mother. He played football and dreamed of being the next Cristiano Ronaldo. He also played rugby, and in 2002, he shook the hand of Queen Elizabeth II when his team took part in her Golden Jubilee. Idris’s elder siblings—three brothers and two sisters—have all gone on to corporate careers in law, business, and IT, so when he realised a professional football career wasn’t going to happen, he ended up studying drama at Brunel University London. He received a BA Honours degree in Theatre, Film & Television studies.

Idris had his first big screen part in 2016 in the British thriller City of Tiny Lights, starring Riz Ahmed. In 2017, he made his American film debut in Megan Leavey alongside Kate Mara, who plays the title character in the eponymous war film. Idris also has a part as an FBI agent in the 2018 film The Commuter with Liam Neeson; and starred in Farming, alongside Kate Beckinsale. Farming is a semi-autobiographical story of Nigerian-British actor Adewale Akinnuoye-Agbaje, who directed the film. Idris plays the character based on Akinnuoye-Agbaje, who, like many Nigerian people in the late 20th century, was “farmed out” to a white family in the UK in the hopes of a better life, while Beckinsale portrays his strict foster mother. In 2019, Damson won the Award for Best Actor in a British Film at the Edinburgh Film Festival for his portrayal. He also appears in “Smithereens,” the second episode of the fifth season of the anthology series Black Mirror.

Idris’s breakout role is Franklin Saint, an ambitious 19-year-old drug dealer in Los Angeles, in the FX crime drama Snowfall from John Singleton, which debuted in July 2017. The first series of Snowfall — set in 1983 as the United States is on the verge of the crack cocaine epidemic — weaves together the stories of several characters whose lives will soon collide because of drugs. Idris auditioned through video in London before flying out to Los Angeles, where he spent the day with Singleton, who wanted to ensure Idris had mastery of the accent. For the role, Idris practised his American accent by studying idol Denzel Washington. He also worked with rapper WC, who tutored him on not just an authentic accent but the mannerisms specific to South Central Los Angeles. Idris earned strong reviews for his performance; Malcolm Venable of TV Guide called him “nothing short of captivating.” The second series of Snowfall, set in 1984, premiered in July 2018.

In May 2017, Idris won the “Emerging Talent Award” at the 12th Screen Nation Film and Television Awards in London.

Idris is a devoted football fan and supports Manchester United. He said his hero is American actor Denzel Washington. In 2017, he told Interview magazine, “[Denzel is] phenomenal. I didn’t know I wanted to be an actor, but once it found me I looked at whom people were saying were great. I looked at who I wanted to be like. Not just in acting, but in their personal life as well. Being a well-rounded person, a fine example of good taste and prestige and class, that’s what I really chased, so he was the person that did it for me.”