Magdalen College School (MCS) is a private day school in the British public school tradition located in Oxford, England, for boys aged seven to eighteen and for girls in the sixth form (i.e. ages sixteen to eighteen). It was founded by William Waynflete in 1480 as part of Magdalen College, Oxford.

The school is run by a headmaster, known since the foundation of the school simply as "the Master" and controlled by a Board of Governors, who appoint the Master. It has both a senior school and a junior school. The Senior School has six houses, names after old attendees of the school who died in the first or second world wars. Each house is headed by a housemaster selected from the senior members of the teaching staff, of whom there are about 160. There are also six houses in the Junior School.

The school was named Independent School of the Year by The Sunday Times in 2004, and 2008, being the first boys' school to attain this accolade twice.