St Lythans is situated north of Barry and west of Penarth in the Vale of Glamorgan, South Wales. It is a rural settlement, more a cluster of houses around the church than a village.

The Valeways Heritage Trail passes within a mile of the village, as it wends its way from St Nicholas, through the village of Dyffryn, and on to Barry.

It is most famous for the ancient burial chamber, or cromlech, St Lythans Burial Chamber. This beautiful chambered tomb stands in splendid isolation (sometimes shared by a herd of cows) in the middle of a field. It was built around 4,000BC, making it older than Stonehenge or the Egyptian Great Pyramid of Giza, and consists of three huge stones. The cromlech might have been used not only as a burial chamber, but also as a ceremonial site.

The medieval parish church of St Lythans is dedicated to St Bleddian. The church holds a Norman font, but was heavily restored by the Victorian architects Prichard and Seddon c.1861. The church houses a large Tudor south chapel, and includes porch, belfry openings and East window. The attractive stone-built west tower is capped by a saddle-back roof so familiar to the Vale of Glamorgan. A footpath crosses the churchyard via a stone stile.