The Honourable William Ross Macdonald, PC, CD, QC (December 25 1891 - May 28 1976), served as the 21st Lieutenant Governor of Ontario from 1968 to 1974 and as Speaker of the Canadian House of Commons from 1949 to 1953.

Born in Toronto in 1891 to a dry goods merchant who had immigrated from Scotland, Macdonald studied Law at the University of Toronto and Osgoode Hall. He practised law in Brantford, Ontario and served with the Canadian Expeditionary Force in the First World War from 1914 to 1918. In 1921 he married Muriel Whittaker.

Macdonald sought the Liberal Party of Canada's nomination to be a candidate in the 1926 Canadian election but lost by a single vote. He succeeded in winning the party's nomination for the 1930 Canadian election but failed to win his seat in Brantford. He was finally elected in the 1935 Canadian election and sat as a Liberal Member of Parliament from 1935 to 1953.

During World War II, Macdonald was a staunch supporter of cumpulsory military service. He served as Deputy Speaker (1945-1949) prior to being nominated Speaker of the House of Commons by Prime Minister Louis St. Laurent following the 1949 Canadian election.

In 1953 he was appointed to the Canadian Senate by St. Laurent and became Leader of the Government in the Canadian Senate and a minister without portfolio in the Canadian Cabinet. From 1954 until the Liberal government's defeat in the 1957 Canadian election, Macdonald seved as Solicitor General of Canada.

With the defeat of the Liberals he became Leader of the Opposition in the Canadian Senate before serving again as Government Leader when the Liberals returned to power in 1963 before retiring from Cabinet in 1964.

Lester Pearson appointed Macdonald to serve as Lieutenant Governor from 1968 to 1974. He was involved with many service groups, such as the Canadian Order of Foresters and the Kiwanis Club.

In 1974 he was made an Officer of the Order of Canada and the Ontario School for the Blind in Brantford was renamed The W. Ross Macdonald School in his honour.

He died in Toronto in 1976.