Father Albert Taylor, the first pastor of Saint Stephen Church, founded Saint Stephen School in September of 1964. Staffed by the Sisters of Mercy, the school served students from grades one to three from Hamden and neighboring towns. A grade was added each year until 1969 with the completion of eighth grade. 1970 marked the first graduation and the establishment of the Home School Association.
Due to an area consolidation of Catholic schools in 1989, grades seven and eight were moved to a Catholic middle school and a kindergarten class was established. In 1990, an after school program was implemented, and a playground was constructed. Grades seven and eight were reestablished at Saint Stephen and a pre-kindergarten program was initiated in 1992. This year also marked the formation of a coeducational sports program. Three years later, a School Board, Advancement Committee, and computer center in the grade six classroom were established.
The issue of additional space was addressed through the completion of the library/media center, known as the Corcoran Center, which was dedicated in November 2005. During the 45 years since its inception, more than 750 students have graduated from Saint Stephen School.