St. Mary's School, Nairobi is an international day Catholic private school founded in Parklands in 1939 by the Holy Ghost Fathers from Blackrock College in Dublin. The Junior School follows the Competency Based Curriculum (CBC) and the Cambridge Primary Curriculum, while the Senior School offers Cambridge IGCSE, KCSE and the International Baccalaureate Diploma Programme (IBDP). The school serves students aged 6 to 18, with admissions for KCPE, Cambridge Primary Curriculum, KCSE, IGCSE and IB. The campus supports a safe learning environment and features three technology centers (Junior, Senior and IB), science laboratories (Biology, Physics and Chemistry), ART rooms, libraries and a Music Center with a recording studio. Notable co‑curriculars include EAMUN and MSMUN Model United Nations, World Scholars, and extensive sport, theatre and music programs. Programs such as CAS and the President's Award foster service, leadership and global awareness alongside academics. The school maintains Catholic values and supports international families.