Llanddewi Rhydderch is a village in Monmouthshire, Wales at OS grid reference SO 351130.

It is off the B4233 road, roughly five miles (8 km) southeast of Abergavenny, lying within the administrative community of Gobion Fawr.

The township of Llanddewi Rhydderch grew around the small llan, or monastic cell named after St. David.

[1] A Baptist chapel on the edge of the village is a Grade II listed building and holds services every Sunday.

[2][3] Josh Wardle, the developer of the web-based word game Wordle, was brought up in the village.