He was born in Brooklyn, New York City, in 1983 to an Armenian-American father – whose family fled the genocide – and a German mother.
He also appeared alongside James Franco and Heather Graham in About Cherry, which premiered at the 2012 Berlin International Film Festival.
In 2014, Patel starred alongside Robert Sheehan and Zoë Kravitz in the film, The Road Within, about three unlikely friends, one with Tourette's syndrome (Sheehan), one with OCD (Patel) and an anorexic woman (Kravitz) who go on a road trip. 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.
For the latter, he won the BAFTA Award for Best Supporting Actor and was nominated for the Golden Globe, Critics' Choice Award, SAG Award, and the Academy Award for Best Supporting Actor.
He was given the Best Actor award for his performance.
Patel later attended Whitmore High School, receiving an A* in GCSE Drama for his "self-penned portrayal of a child in the Beslan school siege".