David Kenneth Roy Thomson, 3rd Baron Thomson of Fleet (born 12 June 1957) is a Canadian media magnate. He is the son of the late Kenneth Thomson, 2nd Baron Thomson of Fleet and his siblings are Taylor Thomson and Peter Thomson. He became the chairman of Thomson Corporation in 2006 at the death of his father and after the acquisition of Reuters, became the chairman of the merged entity, Thomson Reuters in 2008. He currently resides in Toronto, Ontario.