The history of Walla Walla Catholic Schools dates back to 1864 when the Sisters of Providence established St. Vincent Academy for Girls. A year later, St. Joseph's for boys was founded, it was later known as St. Patrick Academy for boys. From 1899 to 1920 the boys' school was operated by the Christian Brothers and known during this era as LaSalle Institute for Boys.
In 1920, the LaSalle building also housed the growing grade school. By 1928 a new school was built and St. Patrick's Grade School for girls and boys and opened that same year and operated until 1969.
In 1932, St. Vincent Academy and St. Patrick's High School were merged to form St. Vincent's High School. In 1940 it became known as St. Patrick's High School. By the 1950's, growing enrollment and a need for more modern facilities prompted the construction of DeSales High School, which opened in 1959.
Assumption Grade School opened its doors in 1955 and served as both school and place of worship for 12 years until construction of Assumption of the Blessed Virgin Mary Parish was completed. The school was operated under the guidance of the Dominican Sisters of Tacoma until the end of the school year in 1970. The school closed when the Sisters withdrew their services and reopened in the fall of 1972 structured to serve all three local parishes in grades 1-6. The first Kindergarten class was held in 1978.
In the fall of 1987 the Assumption Childcare/Preschool program (now the Early Learning Center) began offering preschool, extended care and daycare.
In 1991, students in grade 6 moved from Assumption to DeSales to establish a middle school there with grades 6-8. In the fall of 2005, these grades returned to Assumption and the structure we have today was established with Assumption providing education for life in preschool through grade 8 and DeSales grades 9 through 12.