O'Neill notched a career 17-6 record as a pitcher for the Holy Cross Crusaders baseball team.[1] He pitched three complete-game victories in six days to lead Holy Cross to victory in the 1952 College World Series.[2] He was the first pitcher to win three games in a single College World Series.[3] He was named starting pitching on the 1952 College Baseball All-America Team.[2] He was inducted into the College of the Holy Cross Hall of Fame in 1980.[1]
Basketball
O'Neill played on the Holy Cross Crusaders men's basketball team from 1949 to 1952. He averaged 1.5 points per game for the Bob Cousy-led Crusader team that tied the school record for wins (27) and played in the 1950 NCAA basketball tournament.[4][1] He average 5.6 points per game and 7.6 rebounds per game as a junior and 6.2 points per game as a senior.[5]