Cemaes is a village on the north coast of Anglesey in Wales, sited on Cemaes Bay, an Area of Outstanding Natural Beauty which is partly owned by the National Trust. It is the most northerly village in Wales. The name Cemaes derives from the Welsh word cemais, meaning "bend or loop in a river, inlet of sea, bay". In 2011 the population of Cemaes in Llanbadrig community was 1,357. The most northerly point in Wales, Ynys Badrig, is nearby.

Anglesey is an island off the north-west coast of Wales. It forms the bulk of the county known as the Isle of Anglesey, which also includes Holy Island and some islets and skerries. The county borders Gwynedd across the Menai Strait to the southeast, and is otherwise surrounded by the Irish Sea. Holyhead is the largest town, and the administrative centre is Llangefni. The county is part of the preserved county of Gwynedd.