Aleksander Wachniewski (Polish: [a.lɛkˈsan.dɛr vaxˈɲɛf.ski]; 1881–1976) was a Polish engineer and politician. He was a member of the Polish Workers' Party, and served as the government plenipotentiary in Wrocław, Poland from 13 June 1945 to 15 February 1947, which was an equivalent to an office of the mayor.