[12] As a child, Patel was a fan of action movies after he snuck downstairs and saw scenes from a Bruce Lee film on his parents' TV set.

His drama teacher Niamh Wright said, "Dev was a gifted student, who quickly impressed me with his innate ability to communicate a wide variety of characters imaginatively and creatively.

He was awarded full marks for his GCSE performance to a live audience, and the visiting examiner was moved to tears by his honest portrayal.

He made it to the semi-finals, where he lost to an Irish black belt, named Niall Fitzmaurice, in "a very close and tough fight" and ended up winning a bronze medal.

[18] In 2006, Patel's professional acting career began when he auditioned for the E4 teen drama television series Skins.

[6] The characterisation of Anwar was partly based on Patel's own personality, as the role was developed specifically for him once he was cast in Skins.

[24] The Jamal Malik character is an Indian Muslim boy born and brought up in the poverty of Bombay, India.

[25] Boyle considered hundreds of young male actors, but found that Bollywood leads were generally "strong, handsome hero-types", not the personality he was looking for.

[55] From 2012 to 2014, Patel had a supporting role in the 2012 HBO television series The Newsroom as Neal Sampat, blogger for news anchor Will McAvoy.

[56] He also appeared alongside James Franco and Heather Graham in About Cherry, which premiered at the 2012 Berlin International Film Festival.

Variety had positive words for the "bristling and committed performances by Robert Sheehan, Dev Patel and Zoe Kravitz" while noting that "there remains a nagging tidiness to the whole endeavor that leaves a strained, cloying aftertaste" that kept the movie from truly succeeding.

[57] In 2015, Patel acted in Chappie as an engineer who helps design police robots and as the mathematician Srinivasa Ramanujan in the biopic The Man Who Knew Infinity.

In 2019, Patel starred as the titular character in Armando Iannucci's adaptation of Charles Dickens' The Personal History of David Copperfield, for which he received a nomination for the 2021 Golden Globe Award for Best Actor – Motion Picture Musical or Comedy.

[65][66] He also returned to television in an episode of the Amazon Prime anthology Modern Love, for which he received an Emmy nomination.

[76] Patel will executive produce and star in the Miramax miniseries The Key Man as disgraced businessman Arif Naqvi,[79] and will join Olivia Colman in Wicker.

[84] In August 2022, Patel featured in the local news after he broke up a fight in Gouger Street in Adelaide city centre.

[85] The couple posed for photographs together for the first time on the red carpet at the Los Angeles premiere of Patel's debut feature as a director, Monkey Man, on 2 April 2024.