Cormac Breslin (25 April 1902 – 23 January 1978) was an Irish Fianna Fáil politician. He was born in Gweedore, County Donegal. He was educated at Saint Eunan's College, Letterkenny. He was first elected to Dáil Éireann as a Fianna Fáil Teachta Dála (TD) for the Donegal West constituency at the 1937 general election.Breslin was re-elected at every election until his retirement in 1977. He served as Ceann Comhairle (chairman) of Dáil Éireann from 1967 to 1973.