Patrick Sarsfield "Paddy" Donegan (29 October 1923 – 26 November 2000) was an Irish Fine Gael politician.
He was educated at a Christian Brothers School in Drogheda, County Louth and at the Vincentian Castleknock College, County Dublin. Donegan was first elected as a Fine Gael Teachta Dála (TD) for the Louth constituency at the 1954 general election. He lost his seat at the 1957 general election but was elected to Seanad Éireann by the Agricultural Panel. He regain his Dáil seat at the 1961 general election. In the Fine Gael-Labour Party coalition government which took power after the 1973 general election Donegan was appointed as Minister for Defence.
In October 1976, Donegan made a controversial speech on an official visit to the opening of new kitchen facilities in an army barracks at Mullingar. He described as a "thundering disgrace" President Cearbhall Ó Dálaigh's refusal to sign the Emergency Powers Act, 1976, instead using his powers under Article 26 of the Constitution to refer it to the Supreme Court. The Taoiseach, Liam Cosgrave, refused Donegan's resignation, and instead Ó Dálaigh resigned as President of Ireland. The whole episode badly damaged the government's reputation.
In 1976, Donegan became Minister for Lands, and, in 1977, he served briefly as Minister for Fisheries. Donegan retired from politics at the 1981 general election, and died in 2000. He was buried in his home town of Monasterboice.