Fazal made his Bollywood debut with a special appearance in 3 Idiots (2009) and he next appeared in Always Kabhi Kabhi (2011). His first success came in Fukrey (2013), and he was seen in supporting roles in films like Baat Ban Gayi (2013), Bobby Jasoos (2014) and Sonali Cable (2014).
He played the leading role in the horror film Khamoshiyan (2015) followed by his first American film Furious 7 (2015). He also played a role in Happy Bhag Jayegi opposite Diana Penty in 2016.
Fazal starred in the British-American film Victoria & Abdul, which depicts the relationship of Queen Victoria (Judi Dench) and her confidant, Indian servant Abdul Karim (Fazal). The film premiered at the Venice Film Festival in 2017. The costumes worn by the lead actors in the film have been added as part of the official display at Osborne House.
In 2018, he played Guddu Pandit in Mirzapur.