List of Famous people born in Ontario, Canada

Adam Logan is a research mathematician and a top Canadian Scrabble player. He won the World Scrabble Championship in 2005, beating Pakorn Nemitrmansuk of Thailand 3–0 in the final. He is the only player to have won the Canadian Scrabble Championship five times. He was also the winner of the 1996 National Scrabble Championship, North America's top rated player in 1997, and the winner of the Collins division of the 2014 North American Scrabble Championship.

Alfred E. Humphreys was a Canadian actor.

Allan Michael Rock is a Canadian lawyer, former politician, diplomat and university administrator. He was Canada's ambassador to the United Nations (2004–2006) and had previously served in the Cabinet of Jean Chrétien, most notably as Justice Minister (1993–1997) and Health Minister (1997–2002).

Andrew Gunn is a Canadian film producer. His production company, Gunn Films, was started in 2001. He has worked with Walt Disney Pictures to produce movies such as Freaky Friday and Sky High. Gunn was born in Toronto, Ontario, Canada.

Donald Lake is a Canadian actor, writer, and television producer. He is frequently cast by director Christopher Guest, and is also a close friend and the collaborative partner of Bonnie Hunt.

Christopher Shyer is a Canadian-American actor who has appeared in over 50 film and television roles.

Enrico Colantoni is a Canadian actor and director, best known for portraying Elliot DiMauro in the sitcom Just Shoot Me!, Keith Mars on the television series Veronica Mars, Louis Lutz on the short-lived sitcom Hope & Gloria, crime lord Carl Elias on Person of Interest, and Sergeant Greg Parker on the television series Flashpoint. He has also had supporting roles in such films as The Wrong Guy, Galaxy Quest, A.I. Artificial Intelligence, Contagion, and A Beautiful Day in the Neighborhood, and guest appearances on Monk, Numb3rs, Party Down, Stargate SG-1, and Bones. More recently, he starred as Allen Conner in Remedy. He played Laura Hollis's father in season three of the online web series Carmilla. He most recently appeared as Whitman, a pharmaceuticals rep in HBO's Westworld revival. Colantoni directed two episodes of the TV series iZombie.

James Hayward is a Canadian-born, American based film director, screenwriter, and animator.

Sir William Osler, 1st Baronet, was a Canadian physician and one of the four founding professors of Johns Hopkins Hospital. Osler created the first residency program for specialty training of physicians, and he was the first to bring medical students out of the lecture hall for bedside clinical training. He has frequently been described as the Father of Modern Medicine and one of the "greatest diagnosticians ever to wield a stethoscope". Osler was a person of many interests, who in addition to being a physician, was a bibliophile, historian, author, and renowned practical joker. Outside of medicine, he was passionate about medical libraries and medical history and among his achievements were the founding of the History of Medicine Society, at the Royal Society of Medicine, London. In the field of librarianship he was instrumental in founding the Medical Library Association of Great Britain and Ireland, the Association of Medical Librarians with three others, including Margaret Charlton, the medical librarian of his alma mater, McGill University. He left his large history of medicine library to McGill, where it continues to exist as the Osler Library.

Charles Dennis is a Canadian actor, playwright, radio actor, journalist, author, director, and screenwriter.