Garrison Forest School was founded in 1910 by Mary Moncrieffe Livingston. Montcrieffe adopted the motto Esse Quam Videri—To Be Rather Than To Seem for her then-fledgling school. Nearly 100 years later, those words encourage students to be who they are, not who they think others want them to be. G. Peter O'Neill, Jr. has been the Head of Garrison Forest School since 1994, and has been serving as a head of independent schools for 24 years. A nationally respected educational leader and advocate for girls’ education, Mr. O’Neill was recognized as one of the country's most outstanding school heads in 2006 by the Klingenstein Center at Columbia University.
Located on 116 acres (0.47 km) outside of Baltimore, the school’s park-like campus offers collegiate-quality academic, athletic, arts, residential, and student facilities. Garrison Forest School is accredited by the Middle States Association of Colleges and Secondary Schools and the Association of Independent Maryland Schools.