Caldey Island (Welsh: Ynys Bŷr) is a small island near Tenby, Pembrokeshire, Wales, less than 1 mile (1.6 km) off the coast. With a recorded history going back over 1,500 years, it is one of the holy islands of Britain. A number of traditions inherited from Celtic times are observed by the Cistercian monks of Caldey Abbey, the owners of the island.
The island's population consists of about 40 permanent residents and a varying number of Cistercian monks, known as Trappists. The monks' predecessors migrated there from Belgium in the early 20th century, taking over from Anglican Benedictines who had bought the island in 1906 and built the extant monastery and abbey but later got into financial difficulties. Today, the monks of Caldey Abbey rely on tourism and making perfumes and chocolate.