Khemu's family lived in Srinagar during his early years and he got initial education from Burn Hall School, but his family had to flee to Jammu during their religious exodus after an insurgency erupted in Kashmir during the 1990s. Later, his family stayed in the suburban Mira Road neighbourhood of Mumbai. He finished his schooling from N. L. Dalmia High School in Mira Road and later attended Narsee Monjee College of Commerce and Economics in Vile Parle for his further studies. He now lives in Khar.
His paternal grandfather, Moti Lal Kemmu was a Kashmiri playwright, and a recipient of the Sahitya Akademi award in 1982 for his contribution to Kashmiri literature, and the Padma Shri.
He played the lead in the 2005 film Kalyug, which was directed by Mohit Suri. Kalyug was based on the pornography industry. In 2007, his first release was Madhur Bhandarkar's Traffic Signal, where he played a street-smart money lender who lends money to poor families, but always gets it back with interest.
In 2012, he worked in Mukesh Bhatt's Blood Money, in which he played the lead role as Kunal Kadam, an honest and hard worker who is unknowingly taken into the dark side of diamond trade by his Boss. He co-starred in Go Goa Gone, a zombie comedy film, which was released on 10 May 2013. Both the films were Box office Hits. Go Goa Gone has achieved a cult status for its offbeat humour and genre-bending approach.
In 2015, after over a two-year break, he returned to the screen with the thriller Bhaag Johnny about a man who gets to live two lives with the help of a jinn, portrayed by director Vikram Bhatt. Though the film began shooting in 2013, it was released on 25 September 2015 to mixed reviews, and box office collections were not up to the mark. His second release of the same year was the comedy film Guddu Ki Gun, in which he appears in the title role along with Sumeet Vyas.
Subsequently, he portrayed the fictional role of pro-partition separatist Abdul Khan in the 2019 ensemble period drama Kalank alongside Varun Dhawan and corrupt cop Michael Rodrigues in Suri's Malang (2020). He then made his debut as writer and director with the comedy thriller Madgaon Express (2024), which received positive reviews, for which he won IIFA Award for Best Directorial Debut and Filmfare Award for Best Debut Director.
In 2026, he wrote, directed and starred in the film Vibe, which was a spin-off based on his character from Madgaon Express.
Khemu began a relationship with actress Soha Ali Khan in 2009. Khemu got engaged to Khan in July 2014 in Paris, and married her in Hindu wedding ceremony in Mumbai on 25 January 2015. Khan gave birth to their daughter, Inaaya Naumi Khemu on 29 September 2017.
