Thomas Mullen (c. 1897–2 January 1966) was an Irish teacher and Fianna Fáil politician.
Mullen was born in Roemore, Breaffy, County Mayo, to national-school teacher parents, Thomas and Mary. He was educated in St. Jarlath's College, Tuam, and University College Galway. He too became a teacher and taught in Tullamore and North Brunswick St and at St Saviour's, Denmark St, Dublin.
Mullen became active in the Irish Republican Army after the 1916 Rising. He was the organiser of the escape from Rath Camp in the Curragh Camp during the Irish War of Independence. During the Irish Civil War, he was leader of the Tintown No 1 internment camp of 61 prisoners.
He was elected to Dáil Éireann as a Teachta Dála (TD) for the Dublin County constituency at the 1938 general election. He did not contest the 1943 general election.
He was a brother to Eugene Mullen, a TD for Mayo from June to September 1927.
Mullen died in St Mary's Hospital, Phoenix Park. His last residence was 92 St Assam's Ave, Raheny, Dublin. He was survived by his wife, Louie (nee Ryan), and three daughters, Nuala, Una and Aideen.
He was buried at St. Fintan's Cemetery, Sutton.