Alex Lindsay Clark (born 24 July 1856) was a Scottish-born South African trade union leader and broadcaster. Born in Carnoustie in Scotland, Clark was educated at the Free Church Grammar School. He emigrated to Durban in 1881, where he worked on the railways for many years. He joined the Natal Railwaymen's Association, serving as its president in 1907/08, and then in 1918 was the founding president of the National Union of Railways and Harbour Services.