Walter Cunningham Thomson (1895-1964) was first elected to the Canadian House of Commons in 1949. In 1950 he was elected leader of the Ontario Liberal Party, defeating social reformer Harry Cassidy, but in the 1951 election he failed to win a seat and led a campaign that saw the Liberals drop from 13 to 7 MPPs. He remained leader of the party for another three years due to its state of disorganization before being replaced by Farquhar Oliver in 1954.

Preceded by: Farquhar Oliver

Ontario Liberal leaders

Succeeded by: Farquhar Oliver