Born in Bridgnorth, Shropshire, O'Connor served with the Highland Light Infantry and the West African Frontier Force during World War I. He was called to the bar in 1919, and became a bencher of the Inner Temple in 1936.
He was elected to the House of Commons at the 1924 general election, as Member of Parliament (MP) for Luton, but lost his seat at the October 1929 general election to the Liberal candidate, Leslie Burgin. He was appointed a King's Counsel that year.
At the time of his death, was serving as Solicitor General, a position he had held since 1936 .
- Hansard 1803–2005: contributions in Parliament by Terence O'Connor