A three-year varsity starter, O'Malley was known as a ferocious rebounder, recording over 20 rebounds on several occasions.  As a senior captain, he led the Metropolitan Conference in scoring and rebounding and received First Team Metropolitan All-Conference All-Star recognition, as well as being named Team MVP.  An ECAC All-East All-Star Team member, he was drafted in the 19th round of the 1969 NBA Draft by the Atlanta Hawks, and appeared in 24 games during the 1969-70 season.  A Dean's List student, O'Malley was a nominee for the Alumni Medal and was a member of the Thomas Moore Law Society.