St Ellyw's Church, Llanelieu, is a redundant church in the village of Llanelieu, Powys, Wales. It has been designated by Cadw as a Grade I listed building, and is under the care of the Friends of Friendless Churches. It is sited at the edge of the Black Mountains within the Brecon Beacons National Park. The church dates from the 13th century with additions in the 15th century. The south porch was built in the 16th century. In 1905 Baldwins of Brecon carried out a restoration, and added a bell turret. Further repairs were undertaken in 1981. The church was acquired by the charity, the Friends of Friendless Churches, in 1999. The charity holds a 999 year lease with effect from 19 November 1999.