O'Connell was a key member of some of the greatest basektball teams in Crusader history, including the 1946-47 squad which had a record of 27-3, and won the NCAA championship at Madison Square Garden by defeating Navy, CCNY and Oklahoma. In the championship game, O'Connell's 16 points were second only to teammate and tournament MVP George Kaftan's 18 points. O’Connell was a key member of the 1947-48 team which won the Sugar Bowl, went 26-4 overall and came in third place at the national championships, losing in the semifinal round to Kentucky, 60-52. He was elected co-captain in the 1948-49 squad and had his best individual effort against Brown in his final game as a Crusader, scoring 27 points. He played on Crusader teams which had an overall record of 84-16 (84% winning percentage). At the time of his graduation in 1949, he was the third leading scorer in HC history with 782, ranking behind All Americans Kaftan and Bob Cousy. O’Connell enjoyed a pro career with the Boston Celtics after graduation.