Arthur (Art) O'Connor (1888 – 10 May 1950) was an Irish politician, lawyer and judge. He was born in 1888, the second son of Arthur O'Connor of Elm Hall, Celbridge, Co. Kildare (1834-1907) and his second wife Elizabeth (née Saul). He was educated at Blackrock College, Co. Dublin. He obtained the dispensation which was at that time required by Catholics in order to study engineering at the then almost exclusively Protestant Trinity College, Dublin, from which he duly graduated in 1911.
O'Connor was elected Sinn Féin MP for Kildare South in the 1918 general election. In January 1919 Sinn Féin MPs, who had been elected in the Westminster elections of 1918 refused to recognise the Parliament of the United Kingdom and instead assembled as a unicameral, revolutionary parliament called Dáil Éireann. In the 1st Dáil, he was appointed Substitute Director of Agriculture during the absence of Robert Barton. In the 2nd Dáil he held the position of Minister of Agriculture from 26 August 1921 to 9 January 1922. O'Connor subsequently opposed the Anglo-Irish Treaty and joined the Republican side. He lost his Dáil seat in 1923 general election and failed to be elected again in 1927. He retired from politics, returned to Trinity College Dublin to study law, after graduating in law he was called to the bar, subsequently appointed as Senior Counsel, eventually being appointed Circuit Judge for Cork city.
He never married and died suddenly at his family home, Elm Hall in 1950, and is buried in Donacomper Cemetery, Celbridge. His brothers were also involved in the Irish Republican movement and his sister Fanny was a member of Cumann na mBan. His brother Daniel was the State Solicitor for Kildare. He was a first cousin of Seamus O'Connor, a Dublin solicitor who was also involved in the Irish Republican movement (one of those who met at Wynns Hotel, Dublin on 11 November 1913 to found the Irish Volunteers) and who was later appointed the Sheriff of the City of Dublin.