Week St Mary is situated in the Deanery of Trigg Major and the Hundred of Stratton. It is bounded on the North by Marhamchurch, on the East by Whitstone, North Tamerton and Boyton, on the South by North Petherwin and a detached part of Jacobstow, and on the West by Jacobstow and Poundstock. The parish is in North-East Cornwall between the Devon border and the coast. It is mentioned in the Domesday Book of 1086. The village of Week St Mary is the only village in the parish.