A native of Rutland, MA, O'Connor was a three-way player for the Crusader football team, playing end and serving as the team's place kicker. He kicked three field goals in a 22-0 victory over Boston College in his senior season. Upon graduation, O'Connor received his medical degree from Harvard and practiced Ob-Gyn for many years in Worcester and Boston. He was a Founder and Past President of the New England Obstetrical and Gynecological Society. He also had a distinguished military career. During World War I, he was one of only two physicians to become a line officer in the conflict. He won many decorations and retired with the rank of a Brigadier General.