William Johnston Tupper KC (29 June 1862 – 17 December 1947[1]) was a politician and office holder in Manitoba, Canada.

Later in the same year, Tupper enlisted as a private in the Canadian army to assist in putting down the North-West Rebellion, and remained in Manitoba afterwards.

Tupper ran against Winkler again in the 1915 election, and lost again[1] by an increased margin amid a disastrous provincial defeat for his party.

[citation needed] In 1931, Tupper was elected president of the Law Society of Manitoba, holding the position for three years.

[1] The position was largely ceremonial by this time, and Tupper had little influence over the government of John Bracken.