Saint Mary's School, commonly known as Saints, is a private Roman Catholic primary and secondary day school for boys located in Nairobi, Kenya. Administered by the Roman Catholic Archdiocese of Nairobi, the school offers KCPE, KCSE, IGCSE and IBDP certification. The school admits female students for the IB Diploma Programme. The school's motto is "Bonitas, Disciplina, Scientia", which is Latin for "Goodness, Discipline, Knowledge".