Llanddeiniol is a village and parish in Ceredigion, Wales. The village which lies about seven miles south-west of Aberystwyth, just half a mile off the main A487 coastal road mid-way between Llanrhystud and Blaenplwyf. The parish takes its name from the dedication of its church to St. Daniel, which is situated close to the shore of Cardigan Bay.

There are several walking trails and rights of way in the surrounding countryside and the scenic cliff-top Ceredigion Coastal Path and the All Wales Coastal Path is less than a mile from the village.

Llanddeiniol church is pleasantly situated on the brow of a hill. The church has a castellated tower, with a nave, divided by a double screen into two parts, the eastern of which forms a chancel: the font, which is octangular, is supported on a circular shaft, and placed in the north-western angle of the nave.

The Elim Chapel in Llanddeiniol was built in 1832. One of the prime movers behind the chapel's development was Edward Morris. A few years later Edward led a surge of villagers who emigrated from Llanddeiniol to Ohio, USA. Starting as farmers the men worked in the sawmills and the steel industry before moving to Minnesota to work on the prairies. In America they founded a Capel Elim, which although it has now disappeared, the graveyard still sits in the middle of a field of maize.

In 1899 the Llanddeiniol chapel was revamped and in 1999 a centenary celebration was held.