​Catholic education in the Crescenta Valley began in 1946 with the opening of Holy Redeemer School in Montrose.  When the school opened it was staffed by the Sisters of Charity of the Blessed Virgin Mary.  In 1956 St. James the Less School opened in La Crescenta  with 4 classrooms and 200 students.  The Daughters of Mary and Joseph​ was the founding order of the school. The order remained a part of the school until June of 2001.

St. James the Less Parish and Holy Redeemer Parish became a twinned parish in 2007 with one pastor. In 2009 the two schools combined to help sustainability.  In the fall of 2012, we added a Transitional Kindergarten to the St. James campus. In the fall of 2015 all classes were moved onto the St. James campus.  In the Fall of 2021, the school adjusted its instructional model to meet the needs of our students and the community. Students experience an education where teachers work with educational coaches in grades TK-5 to deliver high quality small group and individual instruction. The middle school offers "Growth" classes where stduents receive instruction to help them grow in mastering the subjects they learn throughout the day. ​Each grade is capped at 15 students, which allows for targeted and strong instruction throughout the school year.