Michael Joseph Hennessy was an Irish politician and businessman. He was first elected to Dáil Éireann as a Businessmen's Party Teachta Dála (TD) for Cork East and North East at the 1922 general election. He was elected as a Cumann na nGaedheal TD for Cork East at the 1923, June 1927 and September 1927 general elections. He lost his seat at the 1932 general election.