His first role was in a 1993 BBC Radio play called Kai Mei Sauce, written by Kevin Wong. He appeared as Errol Spears alongside Sean Lock in the situation comedy 15 Storeys High, and as Franklin Fu in the second series of Look Around You.

In 2003, Wong was nominated at the British Independent Film Awards for Best Supporting Actor for his role as Guo Yi in Dirty Pretty Things.

In 2007, Wong starred in the feature film Grow Your Own.

In 2012, Wong appeared in the Ridley Scott film Prometheus as ship’s pilot Ravel.

In 2013, Wong was cast in the lead role of #aww: The Arrest of Ai WeiWei at the Hampstead Theatre. Shortly after, the Almeida Theatre announced that Wong had joined the cast of the play Chimerica.

Also in 2013, Wong played the role of gangster Lau in the BBC Two comedy-drama The Wrong Mans.

In 2013, Wong was nominated for the West End Frame award for Best Dramatic Performance 2013, for his role as Zhang Lin in Chimerica.

In 2014, Wong played the role of Kublai Khan in the Netflix series Marco Polo, which on 7 January 2015 was renewed by Netflix for a 10-episode second series.

The next year, he appeared in another Ridley Scott science fiction film, playing the director of the Jet Propulsion Lab, Bruce Ng in The Martian. In 2016, he co-starred as Wong in the superhero film Doctor Strange and later reprised the role in the crossover films Avengers: Infinity War and Avengers: Endgame.

In 2016, he appeared in “Hated in the Nation”, an episode of the anthology series Black Mirror, playing Shaun Li, an agent with the National Crime Agency.

In 2017, he voiced the character of Alex Yu in Arkane Studios’s game, Prey. He also starred in “2036: Nexus Dawn”, a promotional short film prequel to Blade Runner 2049 directed by Luke Scott and co-starring Jared Leto.

He appeared as the scientist Lomax in the 2018 science fiction horror film Annihilation.

In 2019, he performed the voice of the Skeksis general skekVar in the Netflix series The Dark Crystal: Age of Resistance. He also appeared as the voice of Bull in Lady and the Tramp in 2019.

In 2020, he appeared as a Necromancer in Taika Waititi’s ‘What We Do in the Shadows”.