In 1963, Msgr. John Darby, the first pastor of St. Gregory Barbarigo Church, inspired parishioners to create a school where young people could earn a quality Catholic education.  On January 27, 1963, a ground-breaking ceremony occurred followed by the first registration for the school.  In July 1963, the Dominican Sisters of Sparkill announced that Sr. Catherine Florence, OP would become the first principal of St. Gregory School. 

In September 1963, the school year opened even though the building was not yet ready!  The children would attend classes at St. Augustine School and parishioners' homes.  Our first 400 students moved into their new school building on April 6, 1964.  The cornerstone was blessed on Dec. 21, 1963 and Cardinal Spellman dedicated the building on May 30, 1965.  Our first 8th-grade class graduated in June 1967. 

The 1970s were a time of increased enrollment in the parish school.  In the  1980s, an Honors Math program, new library, and foreign language program began while our first full-day Kindergarten opened in September 1987.  Our parish school received accreditation from the Middle States Association in April 1997 and accreditation from AdvancED in 2010.  A new computer lab was created in the summer of 1998 and a new Science lab was installed in the summer of 2006.  In 2007, a playground would be installed for the early childhood education program.  In September 2012, St. Gregory School became a member of the St. Dominic Catholic School Region of Rockland and its principal, Mrs. Cathleen Cassel, will become the regional superintendent.       

On Sunday, June 16, 2013, Cardinal Dolan celebrated the closing Mass for the 50th Jubilee of the school and parish.