Ameen was born in London, to Jamaican and Vincentian parents. He studied acting at the Barbara Speake Stage School, an independent school in London. As a child he appeared in West End in shows such as Oliver! and Jolson. At age 11 he performed on stage with Michael Jackson at the 1996 BRIT Awards in a performance famously invaded by Pulp's singer Jarvis Cocker.

Ameen's first acting role was in 2004's Bella and the Boys, in which he played the character Terry. His next role was a one-off appearance in an episode of the BBC television series Holby City. He also starred in the British youth-centred film Kidulthood as the central character Trife and now he's starring again in Second Chance and Red Tails for a special appearance.

He was named one of The Times newspaper's 'Ones To Watch' for 2006, and won 'Best actor in a TV performance' at the 2007 Screen Nation Awards. Additionally, he presented an award at the Mobo Awards 2006.

In June 2008, Ameen began Actors Student Alliance, a drama school set up to discover and teach untapped talent in London. From its inception, the school has gone on to producing a short film and a theatre showcase for its students. Now in its second year, the school has expanded into a management company.

He performed at Tricycle Theatre on the Not Black and White season in October 2009. Described as "exceptionally charismatic Aml Ameen the freshest, most inspiring voice in the play" by Time Out London. He received outstanding reviews in the National press. Ameen starred in Jason Barrett's British feature film The Naked Poet in which he played character Ryan. For this performance, he won Best Actor at the VIPF Awards in 2010.

Ameen also starred in David E. Kelley's legal drama Harry's Law in the first season, which began to air on NBC during the 2011 television season.

Ameen's first Hollywood film role is in George Lucas's Red Tails (2012), about the African American Tuskegee airman in World War II. He played Alby in the 2014 film adaptation of the young adult, science-fiction, dystopian novel, The Maze Runner.

In 2015, Ameen was one of the eight central characters in the initial run of the Netflix series Sense8, produced by the Wachowskis and J. Michael Straczynski. However, conflicts with the Wachowskis resulted in his replacement with Toby Onwumere after filming two episodes of the second season in 2016.

In 2017, Aml Ameen is set to star as a young Jamaican named “D” in Victor Headley's 1992 cult novel, Yardie. Actor Idris Elba makes his directorial debut with the film in London and Jamaica.