David Kenneth Roy Thomson, 3rd Baron Thomson of Fleet is a Canadian hereditary peer and media magnate. Upon the death of his father in 2006, Thomson became the chairman of Thomson Corporation and also inherited his father's British title, Baron Thomson of Fleet. After the acquisition of Reuters in 2008, Thomson became the chairman of the merged entity, Thomson Reuters.
As of June 2021, Thomson was listed as the wealthiest person in Canada, with an estimated net worth of $45.7 billion.