O'Keefe began his collegiate career in 2017. In his first collegiate game against Robert Morris, O'Keefe scored seven goals, earning him Big Ten Offensive Player of the Week honors. He would break Penn State's single season goals record, which had stood since 1957 with 51, earning honorable mention All-American honors, as well as being named the Big Ten Freshman of the Week six times and the Big Ten Offensive Player of the Week twice. That summer, he played for the Orangeville Northmen of the Ontario Junior Lacrosse League, where he scored 33 points in 15 games.
