Alexander Johnston (April 24, 1867 – November 30, 1951) was a Canadian journalist, civil servant and politician.
Born in Richmond County, Nova Scotia, Johnston was educated at the Common Schools and St. Francis Xavier College, Antigonish, Nova Scotia. He was the editor and proprietor of the Sydney Daily Record. He was elected, in 1897, to the Nova Scotia House of Assembly but he resigned his seat in 1900 in order to contest the riding of Cape Breton for the Canadian House of Commons. A Liberal, he was successful and was re-elected in 1904. He was defeated in 1908. Johnston was Deputy Minister of Marine and Fisheries from 1910 to 1933. He led the Canadian delegation to London which participated in the development of international regulations for safety at sea following the sinking of the RMS Titanic. Johnston was made a Companion of the Order of St Michael and St George in 1935. He died in Ottawa at the age of 84.