Sir John Gladstone Black McDonald (6 December 1898 – 23 April 1977) was 37th Premier of Victoria (leading the Country Party) from 27 June 1950 to 17 December 1952, except for a few days in October 1952 when Thomas Hollway led a brief Electoral Reform League government. McDonald came to office by defeating Hollway's Liberals, but was himself vanquished by the Labor Party under John Cain in 1952. McDonald was also Deputy Premier of Victoria from November 1947 to December 1948 under Premier Thomas Hollway.