Llandevaud (sometimes Welsh: Llandyfawg; also recorded historically in English as Llandevad and Llandevan) is a hamlet in Newport, Wales.

The western part of the hamlet lies on Brownstones formation sandstone formed between 419.2 and 393.3 million years ago in the Devonian period.

The bedrock of the eastern part is the Tintern sandstone formation, formed in the Devonian and Carboniferous periods between 372.2 and 346.7 million years ago.

[2] Two uninvestigated sites are the possible remains of a Roman villa west-southwest of Llandevaud Common[3] and an ancient square cropmark enclosure north of the hamlet near Chepstow Road, of unknown date and function.

The current church structure dates from 1843, built on the remains of its predecessor to a design by Edward Haycock, paved with the old tombstones.

[8] Windows include artwork by Henry Holiday, Robert J. Newbery, John Hall & Sons and Celtic Studios.

[12][10] The Llandevaud National School building was founded and endowed in 1846 by vicar Lewis Jones (who used his salary towards the repair of St. Peter's) and was expanded at later times, accommodating pupils from surrounding hamlets.

The Rising Sun Inn by Newport-Chepstow Road served the hamlet through the 19th and 20th centuries, including holding inquests and auctions.

[21] In the late 1990s, plans for the 486-hectare Legend Court scheme, which would have been the UK's biggest theme park, centred on nearby Pencoed Castle and dramatically affecting Llandevaud, were submitted to Monmouthshire and Newport authorities without success.