Rockville Centre has one private K-8 Catholic day school; The Saint Agnes Cathedral School. The Saint Agnes Cathedral School occupies a single campus. The Saint Agnes Cathedral School provides a day school education for Kindergarten through Eighth Grade for families across Nassau County. The Saint Agnes Cathedral School's upper school (9–12), though now defunct, shared the complex at one time. The school is widely regarded for their consistently high-rated academic program among Long Island private schools, as well as their diverse secondary school placement.