David Thomson, 3rd Baron Thomson of Fleet

He was born on 12 June 1957, in Toronto, Canada, the eldest child of Kenneth Thomson, 2nd Baron Thomson of Fleet and his wife, Marilyn Lavis.[6] He has a sister named Kathy Thomson, and his brother, Peter Thomson, is a race car driver.

In 1978, Thomson received his Bachelor of Arts (subsequently upgraded to an MA (Cantab)) at Selwyn College, Cambridge where he studied history. As a child, he attended both Upper Canada College and the Hall School.

Thomson started his business career as a junior associate at McLeod Young Weir in Toronto. He left the firm to enter the family business, working in a number of positions in companies controlled by the Thomson family. Thomson was manager of The Bay store at Cloverdale Mall in Etobicoke, and president of Zellers. In an effort to develop his independence, Thomson founded the real estate firm Osmington Incorporated, owned and operated outside of the Thomson empire. Osmington acquires and manages commercial real estate assets on behalf of institutional shareholders. In 2010, Osmington sold its stake in eight retail properties to the Canada Pension Plan for $336 million. Osmington is a major investor in FarmersEdge, a precision agriculture company. Osmington is also a partner in True North Sports and Entertainment, owners of the National Hockey League's Winnipeg Jets and the Bell MTS Place in downtown Winnipeg, Manitoba.[9] Osmington is redeveloping the retail space of Toronto's Union Station. Thomson's investment activities are managed through Toronto hedge fund Morgan Bay Capital,

According to a plan devised decades ago by Thomson Corporation founder Roy Thomson, when Kenneth Thomson died (in June 2006), control of the family fortune passed on to David.[10]

Following Thomson Reuter's sale of a controlling stake in its financial business in 2018, Thomson expressed frustrations working in the family business. He is currently engaged in discussions with family members to leave the family business, Thomson Reuters, to focus on his own art and real estate activities.

"David, my grandson, will have to take his part in the running of the Organisation and David's son, too," Roy Thomson wrote in his 1975 autobiography. "With the fortune that we will leave to them go also responsibilities. These Thomson boys that come after Ken are not going to be able, even if they want to, to shrug off these responsibilities."[10]

Thomson is a noted art collector and owns works by Rembrandt, J. M. W. Turner, Paul Klee, Hammershoi, Edvard Munch, Patrick Heron, Joseph Beuys, E. L. Kirchner, and Egon Schiele. Thomson owns the world's largest collection of paintings and drawings by the English painter John Constable. In an interview with Geraldine Norman in The Independent in 1994, Thomson said he bought his first Constable drawing at 19, giving the seller "an oil painting in exchange and quite a lot of money". Norman described him as a "fanatical collector", and Thomson described how he "fell in love" with Constable's style as a young child. In his twenties, Thomson stunned the art world with two monumental purchases. In 1984, he acquired J. M. W. Turner's spectacular 'Seascape: Folkestone", for a record £7.3 million (£21.8 million in 2017) from the sale of the collection of noted British art historian Kenneth Clark. The following year, Thomson, 27, broke another world record when he bought Rembrandt's monumental "Christ Presented to the People", from 1655, for a record £561,000 (£1.7 million in 2017) at Christie's London, when the Duke of Devonshire sold the Chatsworth Collection in one of the largest auctions of the time. Thomson sold both masterpieces within a few years during the 1980s financial crisis.

In 2002, Thomson and his father paid a world record price of $76.7 million to acquire Rubens' "Massacre of the Innocents", now the centrepiece of the Thomson Collection at the Art Gallery of Ontario. In 2012, Thomson shattered records buying a painting by Danish artist Vilhelm Hammershoi, "Ida Reading a Letter", paying the highest price ever for a Danish artist. In 2012, Thomson broke the record for the most expensive 18th-century British watercolour when he paid £2.4 million for a small landscape by John Robert Cozens.

Thomson is an active acquirer of Canadian art. In 2007, Thomson paid $1.8 million for a face mask, the highest price ever paid for a single piece of Native North American art. And in November, 2016 he paid a record C$11.2 million to buy a painting at auction by Group of Seven artist Lawren Harris entitled "Mountain Forms".

Thomson operates his collecting activities through his personal Thomson Works of Art. Thomson also funds the Archive of Modern Conflict, based in London. Specialists within the archive purchase photography collections worldwide and also run a book-publishing arm, AMC Books, which has a Canadian imprint, Bone Idle Books, based in Toronto.

Thomson is the father of six children from four different mothers. With his first wife, Mary Lou La Prairie, he has two daughters: Thyra Nicole and Tessa Lys. With his second wife, Laurie Ludwick, Thomson has one son, Benjamin, born after Thomson left the marriage. With the actress Kelly Rowan, Thomson has a daughter. With his partner Severine Nackers, an employee of Sotheby's in London, Thomson has two daughters, Ottilie, born in 2015, and Elodie, born in 2018. None of the children live with their father. Thomson was estranged from his eldest daughter, Thyra, for five years, with Thyra eventually suing her father over mismanagement of the family trusts. The case was settled out of court in 2017. Thomson lives alone in a private residence that also houses an underground art gallery, in Rosedale, Toronto. Three of his children live in London, UK, where Thomson retains several homes.

Thomson is a patron of the Art Gallery of Ontario. With the death of his father, he became the 3rd Baron Thomson of Fleet on 12 June 2006, his 49th birthday. He does not use this title in Canada. He is an avid art collector and owns the world's top collection of John Constable.[11]

Thomson has rarely given interviews to the press and maintains a low public profile. "The only substantial interview he has given was to James FitzGerald, who wrote a book about the elite private school (Upper Canada College) they both attended in Toronto", according to a July 3, 2006, article in The New York Times. "In his comments to Mr. FitzGerald 12 years ago, David had little positive to say about many people in the business world".[10] In the interview, Thomson said: "When you try to live a more balanced life, traditional businessmen think that you are not a real man. But who is not the real man? You are telling me? You have not taken a weekend with your wife, you have no spare time that you use constructively, you do not have any hobbies, you do not know how to spell Mozart. And here you are telling me that I am weak?"[10]

He resides in Toronto, Ontario.[12]

• Canadian Hereditary Peers
• Archive of Modern Conflict

• The AGO's Other Thomson Patron