Born in Jarrow, Thompson grew up in Corby. He graduated from Cambridge University in philosophy and with a diploma in computing in 1984. He was a correspondent for the technology programme The Big Byte on BBC Radio. He began to write for The Guardian in 1990, and in 1994 went to work there, setting up the paper's website. He left in 1996 to work as a freelance writer and consultant. In November 2009 he took on a role as head of partnership development for Archive Development projects at the BBC, working with Tony Ageh (formerly of The Guardian, now Controller of Archive Development at the BBC).