John Hennigan was an Irish politician and farmer. He was first elected to Dáil Éireann as a Cumann na nGaedheal Teachta Dála (TD) for the Leitrim–Sligo constituency at the 1923 general election.[1] He was re-elected at each subsequent election until lost his seat at the 1933 general election.[2] He was a member of Sligo County Council from 1928–42.