The Lady Kirk (or St Mary's Kirk) at Pierowall is a ruined 17th-century church on the island of Westray, in Orkney, Scotland. The church was built in 1674, on the foundations of the 13th-century church. Two 17th-century grave-slabs, in excellent condition, are set into the interior wall of the chancel and are now protected by glass screens. The graves display fine lettering and 17th-century images of mortality, engraved in high relief. Historic Environment Scotland established the site as a scheduled monument in 2014.