Llanychlwydog 3, a cross-carved stone, stands to the west of the former St David's Church, Llanychlwydog (NPRN 308784). It was first noted in 1883, when it stood in the churchyard. By 1916 it was noted to be prostrate and lying near Llanychlwydog 2. It was re-erected between 1956 and 1964 and when excavated in 1984 had been set into 19th century building rubble. It was removed to Scolton Manor Museum at that time, but was returned to the church before 1992. The stone probably functioned an upright grave marker within the early medieval cemetery excavated within the churchyard. It is one of four early medieval stones found within the churchyard.

The stone is a rough dolerite pillar, dominated by euhedral plagioclase feldspar crystals. Dimensions are given as 117cm height x 54cm width x 17.5 < 41cm diameter. It is carved on one broad face with a linear cross, thought to date to the seventh to ninth century. The carving is very damaged and worn.

Sources include:
Edwards, N. 2007, Corpus of Early Medieval Inscribed Stones and Stone Sculpture in Wales

N Vousden, 19 October 2018