Of mixed English and Kashmiri Pandit ancestry, Kunzru grew up in Essex. He was educated at Bancroft's School, Essex. He studied English at Wadham College, Oxford, then gained an MA in Philosophy and Literature from University of Warwick.

From 1995 to 1997 he worked on Wired UK. He has worked as a travel journalist since 1998, writing for such newspapers as The Guardian and The Daily Telegraph, was travel correspondent for Time Out magazine, and worked as a TV presenter interviewing artists for the Sky TV electronic arts programme The Lounge. In 1999 he was named The Observer Young Travel Writer of the Year. From 1999—2004 he was also music editor of Wallpaper* magazine and since 1995 he has been a contributing editor to Mute, the culture and technology magazine. He won a Betty Trask Award and the Somerset Maugham Award for The Impressionist. Transmission, his second novel, was published in the summer of 2004 and was named one of the New York Times's notable books of the year. In 2005 he published the short story collection "Noise" and in August 2007 Penguin Hamish Hamilton published My Revolutions.

In 2003, Hari Kunzru was named by Granta magazine as one of twenty "Best of Young British Novelists". In 2005, Lire magazine named him one of the world's "50 écrivains pour demain". Although he was also awarded The John Llewellyn Rhys prize for writers under 35, the second oldest literary prize in the UK, he turned it down on the grounds that it was backed by the Mail on Sunday whose "hostility towards black and Asian people" he felt was unacceptable. In a statement read out on his behalf, he stated, "As the child of an immigrant, I am only too aware of the poisonous effect of the Mail's editorial line... The atmosphere of prejudice it fosters translates into violence, and I have no wish to profit from it." He further went on to recommend that the award money be donated to the charity Refugee Council . He is Deputy President of English PEN.

In 2009, he donated the short story "Kaltes klares Wasser" to Oxfam's Ox-Tales project, four collections of UK stories written by 38 authors. Kunzru's story was published in the Water collection.