He was educated at Catholic schools before becoming a clerk, as well as an organiser of the Australian Workers' Union.

In 1946, he was elected to the Australian House of Representatives as the Labor member for West Sydney.

Following that election, one of the defeated candidates for the seat, Ronald Sarina, petitioned the High Court to declare O'Connor's election void, claiming that O'Connor's adherence to the Roman Catholic faith represented allegiance to a foreign power, which would make him ineligible to be a member of parliament under Section 44 of the Constitution of Australia.

In that year, Martin was abolished, and O'Connor defeated sitting Labor MP Arthur Greenup for preselection for the seat of Dalley.

This article about an Australian Labor Party member of the House of Representatives is a stub.