Daniel (Donal) O'Callaghan was an Irish Sinn Féin politician. He was elected unopposed as a Sinn Féin Teachta Dála (TD) to the 2nd Dáil at the 1921 elections for the Cork Borough constituency.[1] He opposed the Anglo-Irish Treaty and voted against it. He stood as an anti-Treaty Sinn Féin candidate at the 1922 general election but was not elected.[2]