Walter Cunningham Thomson (December 21, 1895 – April 27, 1964) was a Canadian politician, lawyer and rancher in Ontario, Canada. He was leader of the Ontario Liberal Party from 1950 to 1954 and was a federal Member of Parliament from 1949 to 1951.
Walter Cunningham Thomson was born on December 21, 1895 in Hastings, Ontario, the son of Reverend David Anderson Thomson and Janet née MacMillan.
On February 29, 1916, he enlisted into the army and was posted to the 93rd Battalion, Canadian Expeditionary Force, as a Lieutenant.
In 1923 he graduated from Osgoode Hall Law School in Toronto, Ontario as a solicitor. On June 25, 1924, he married Greeta Brophy Whitehead in Toronto.
In 1930 they settled on a dairy farm near Pickering, Ontario, where he opened a law practice in 1935.
In 1944 he was appointed as Ontario Solicitor for the Veteran’s Land Act.
Thomson first ran for the leadership of the Ontario Liberal Party at the 1943 leadership convention but came in fourth place losing to Harry Nixon. He was elected to the House of Commons of Canada in the 1949 federal election.