[1] He was the son of William O'Connor and Julia Corbet, both fluent Irish speakers, and was educated by the Christian Brothers at Cork.
A political turning-point came when the constitutional Home Rule League leader Charles Stewart Parnell came on a visit to Cork.
O'Connor was credited with a leading part in a plot laid by Fenians to kidnap Parnell when his train stopped at Blarney station for ticket collecting.
In January 1885, Parnell chose O'Connor as his nominee for a parliamentary by-election for Tipperary, and secured his selection at the Party convention over a strongly supported local candidate.
In the week-long debate in Committee Room 15 of the House of Commons, O'Connor played a prominent role, particularly on the last day when he moved a resolution critical of Gladstone's continued insistence on Parnell's removal from the leadership.
He served as a member of the Royal Commission for the British Section of the Chicago Exhibition, 1893, and a member of the Council of the Royal Society of Arts, and was later chairman of the New Central Omnibus Co. and a Director of the London Central Motor Omnibus Co.[4] In February 1905 he was returned unopposed for North Kildare, which had become vacant on the death of his fellow Parnellite Edmund Leamy.
Thereafter he was returned unopposed until the 1918 general election, when he was defeated by the Sinn Féin candidate Daniel Buckley ( later the last Governor-General of the Irish Free State) by more than 2 to 1.
Maume (1999), however, citing manuscripts in the Redmond papers in the National Library of Ireland, says that at the time of his first election at North Kildare he had an estranged wife who was suing him for maintenance and whom he intended to divorce.