- St. Andrew's Episcopal School opened its doors in Pilgrim Lutheran Church on Massachusetts Avenue in 1978
St. Andrew's has come a long way from the idea of two Episcopal elementary school heads, who saw the need for a coeducational high school for their graduates. In 1978, after three years of planning, St. Andrew's opened in the basement of Pilgrim Lutheran Church on Massachusetts Avenue with 40 students in grades seven, eight and nine, nine part-time teachers, and a school library comfortably housed on four shelves.
- The school grew quickly. From the fall of 1979 through the spring of 1981, the location was in the former Cabin John Elementary School.
Growth by the 1979-80 school year necessitated a move to larger space in Clara Barton Elementary School of Cabin John and only two years later, to the former North Bethesda Junior High School. By the time St. Andrew's graduated its first senior class in the spring of 1982, it had grown to 245 students and 28 teachers and entered the ranks of full-fledged independent college-preparatory schools.
In September 1998, St. Andrew's dedicated its 19.2-acre campus in Potomac, Maryland. Shortly thereafter, the school reached its maximum enrollment of 450 students, grades six through twelve.
Because its roots stemmed from the determination of the founding trustees, St. Andrew's never has forgotten its purpose or convictions: a diversity of students, an emphasis on the arts, a sports program open to all who sincerely try to make a team, and the regular teaching and practice of religion.
- St. Andrew's name went up on the former North Bethesda Junior High School campus on Bradmoor Lane in Bethesda, in September 1981.
The latest big event in St. Andrew’s history occurred on July 1, 2008, when the students and faculty of the former St. Francis Episcopal Day School, of 10033 River Road in Potomac Village, became part of the St. Andrew’s community. St. Andrew’s new Lower School, at the River Road address and called the “Potomac Village Campus” is for students in preschool through Grade 3. In the fall of 2009, a Grade 4 class became part of the Postoak Road Campus. Starting in Fall 2010, St. Andrew's has a Grade 5 class - marking the first time St. Andrew’s offers its distinctive mission to children in preschool through Grade 12!