Oscar Traynor (21 March 1886 – 15 December 1963) was an Irish Fianna Fáil politician and republican. He served in a number of Cabinet positions, most notably as the country's longest-serving Minister for Defence.
Oscar Traynor was born into a strongly nationalist family in Dublin. He was educated by the Christian Brothers in Dublin. In 1899 he was apprenticed to John Long, a famous wood-carver. As a young man he was a noted footballer and toured Europe as a goalkeeper with Belfast Celtic F.C. whom he played with from 1910 to 1912.
Traynor joined the Irish Volunteers and took part in the Easter Rising in 1916. Following this he was interned in Wales. During the Irish War of Independence he was brigadier of the Dublin Brigade of the Irish Republican Army and led the attack on The Custom House in 1921 and an ambush on the West Kent Regiment at Claude Road, Drumcondra on 16 June 1921 when the Thompson submachine gun was fired for the first time in action. When the Irish Civil War broke out in June 1922, Traynor took the republican side. The Dublin Brigade was split however, with many of its members following Michael Collins in taking the pro-Treaty side. Traynor and his supporters tried to help the republicans who had occupied the Four Courts when they were attacked by Free State forces, by occupying O'Connell street. Traynor and his men held out for a week of street fighting before making their escape. He organised guerilla activity in south Dublin and county Wicklow, before being captured by Free State troops in September. He was then imprisoned for the remainder of the war.
On 11 March 1925 he was elected to Dáil Éireann in a by-election as a Sinn Féin TD for the Dublin North constituency, though he did not take his seat due to the abstentionist policy of Sinn Féin. He was re-elected as one of eight members for Dublin North in the June 1927 general election but just one of six Sinn Féin TDs. Once again he did not take his seat. Traynor did not contest the second general election called that year but declared his support for Fianna Fáil. He stood again in the 1932 general election and was elected as a Fianna Fáil TD for Dublin North.
In 1936 he was first appointed to the Cabinet as Minister for Posts and Telegraphs. In September 1939 Traynor was appointed Minister for Defence and held the portfolio to February 1948. In 1948 he became President of the Football Association of Ireland, a position he held until his death. He served as Minister for Defence in several Fianna Fáil governments and as Minister for Justice before he retired in 1961.
Oscar Traynor died on 15 December 1963, in Dublin at the age of 77.
He has a road named in his memory on the Coolock to Santry stretch in North Dublin.