Alexander William Black (28 February 1859 – 29 December 1906) was a Liberal Party politician in Scotland. Originally trained as a lawyer, he was elected at the 1900 general election as the Member of Parliament (MP) for Banffshire, and was re-elected in 1906. However he died in December that year from injuries received in a railway accident at Elliot Junction, forcing a by-election early in 1907. In later life he is listed as living at 5 Learmonth Terrace in western Edinburgh.