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.

O'Connor returned to Parliament seven months later in a by-election in the Nottingham Central constituency, and held the seat until his death in 1940, aged 48.

At the time of his death, was serving as Solicitor General, a position he had held since 1936 .

• Leigh Rayment's Historical List of MPs

• Hansard 1803–2005: contributions in Parliament by Terence O'Connor