John A. Murphy (born 17 January 1927) is an Irish historian and a former senator. He is currently Emeritus Professor of history at University College Cork (UCC).
Murphy was born in Macroom, County Cork, and in 1945 he won a County Council scholarship to study history at UCC. He graduated in 1948 with a first-class honours degree and first place in both History and Latin, then took an MA in Cork before taking up a teaching post at the diocesan seminary at Farranferris in Cork city.
In 1960 he became an assistant lecturer at UCC, and was appointed Professor of Irish History in 1971, holding that chair until his early retirement in 1990. His 1975 book Ireland in the twentieth century was one of the first surveys of contemporary Irish history.
He opposed Ireland's referendum opening marriage to same sex couples. In a letter to the Irish Times published on 13 May 2015, he asserted that he could not be accused of homophobia or bigotry, pointing to the fact that he had supported recognition for an LGBT society in the 1990s at University College Cork, where he taught. In the same letter, he described the proposed constitutional amendment as "grotesque nonsense."