Seán Daniel Treacy (22 September 1923 – 23 March 2018) was an Irish Labour Party politician who served as Ceann Comhairle of Dáil Éireann from 1973 to 1977 and 1987 to 1997.

[1][2][3][4] Author R. M. Douglas wrote that Treacy was a party member of fringe Fascist group Ailtirí na hAiséirghe during the 1940s.

He was expelled from the Labour Party in 1985 for voting against the family planning bill, which would have liberalised the sale of contraception in the Republic of Ireland.

One of his first acts was to exercise his casting vote in favour of the nomination of Charles Haughey as Taoiseach.

[9] His funeral, which was attended by President Michael D. Higgins, Taoiseach Leo Varadkar and former Minister Martin Mansergh, was held on 26 March 2018.