Born in Birmingham, England, on June 19, 1881, Johnston left school at the age of 13 and worked at a variety of jobs. He emigrated to Canada in 1901, and spent a couple of years in Manitoba, before coming to Saskatchewan in 1903 and establishing a successful farm near Cymric. Johnston was involved in the formation of United Farmers of Canada (Saskatchewan Section), and advocated for the organization's entry into electoral politics. In the 1934 provincial election, Johnston finished third in Lumsden for the Farmer-Labor Party (the predecessor of the CCF). In 1935 he challenged Liberal leader Mackenzie King in the federal riding of Prince Albert, but was defeated. Johnston ran for the CCF in the 1938 provincial election in Touchwood and was one of ten CCF MLAs elected that year. Re-elected in the CCF sweep of 1944, Johnston served as Speaker. Re-elected twice, he spent a record twelve years in the Speaker's chair. On one occasion, Johnston took the extraordinary step to leave the Speaker's chair to enter into debate, a right rarely exercised by Speakers. Johnston retired in 1956, but remained politically active. At the age of 80 he sailed around the world on an ocean freighter to get a better understanding of the problems of the developing world. Returning to Saskatchewan, he called for the developed world to face the problems of abject poverty in developing nations. Johnston died in Regina on September 11, 1969.