Saint Mary’s Church is located in the village of Pentraeth, Anglesey, North Wales. It is thought that prior to the building of the present church there was a church on the site dedicated to St Geraint.

Although the present church was much restored in 1882 the lower courses of the north and south walls of the chancel and nave, and most of the west wall are probably mediaeval. The south chapel is possibly late 16th or early 17th century and may have been rebuilt.