William Alexander Campbell (March 31, 1873 – September 6, 1934) was a provincial politician from Alberta, Canada.

He served as a member of the Legislative Assembly of Alberta from 1909 to 1917 sitting with the Liberal caucus in government.

He defeated Conservative candidate John Jackson by a comfortable plurality.

Campbell sought re-election again in the 1913 Alberta general election, where he defeated Independent candidate Percival Baker and Conservative candidate George Gordon in a hotly contested three-candidate election.

Charles Cunningham from the Conservative party defeated Campbell in his bid for a third term in office in the 1917 Alberta general election by a margin of 31 votes.