Murdoch Alexander MacPherson, Q.C. (1891–1966) was a Canadian politician. Universally referred to as "M.A. MacPherson", he was Attorney-General of Saskatchewan under Conservative Premier James T.M. Anderson from 1929 to 1932.
Born at MacPherson House on Cape Breton Island, MacPherson attended law school at Dalhousie University, Halifax, Nova Scotia.
He served in World War I and commanded a company of the 10th Battalion at Battle of Vimy Ridge where he came out unscathed. He was wounded by shellfire, however, at Arleux, near Arras a few days later. MacPherson Avenue in Regina, Saskatchewan was later named in his honour, and is an official memorial of the Canadian Department of National Defence. After the war he practiced law in Saskatchewan and eventually became a Queen's Counsel (Q.C.).
MacPherson was first elected to the Saskatchewan legislative assembly in 1924, and remained a member of the Legislative Assembly until his defeat in the 1934 provincial election that wiped out the Conservative Party. He was called to Ottawa late in the term of the R.B. Bennett government to assist in creating the Farm Credit Corporation. In 1959, he headed a Royal Commission: the MacPherson Commission.