O'Connor was born and raised is Malden, Massachusetts and attended Mystic Valley Charter School. His father works for the
United States Post Office. While at Mystic Valley, Brian was a star on their basketball and football teams. Brian played AAU basketball with Nerlens Noel. During his senior year, Brian was the starting Tight end on their football team.
O'Connor attended UMass Amherst and was accepted to the Isenberg School of Management prior to his arrival; he was a Finance major with a specialization in Risk management.  Brian lived in Southwest for the first two years and stated that getting to live down the hall from Dave Liebowitz was one of his highlights. [✔]
During his time in college, Brian worked for UMass Catering and was also a teaching assistant in Isenberg. In 2015, Brian helped founded the Minutemen Alternative Investment Fund and served as their first Portfolio manager. Under his direction, Brian led a team of four traders to the fund's early success. Brian graduated from UMass in May of 2016.