Aberarth is a village in Ceredigion, Wales, in the community of Dyffryn Arth, on the southern end of Cardigan Bay between Aberystwyth and Cardigan at the mouth of the River Arth on the A487 road. The Wales Coast Path passes through the village.
The village has some historical significance, having been founded around the time of the Norman invasion. The Normans built Dineirth Castle some way up the river valley. During the 12th century Cistercian monks used the area as a seaport to import "Bath Stone" from Bristol which they used for the building of Strata Florida Abbey on land granted to them by The Lord Rhys. Llanddewi Aberarth Church on a hill about half a mile to the south of the village is reputedly on the site of a 9th-century church. The present parish church has a Norman architecture tower with the rest rebuilt in the Victorian era in 1860. Secured to the wall inside the front door is the only Viking hogsback stone found in Wales.
Aberarth was involved in the shipbuilding industry before 1850, but the village faded with the decline of the industry.
In 2005, a public footpath and cycle lane was finished, connecting Aberarth to its larger neighbour, Aberaeron.
- Hywel Teifi Edwards (b. 1934 - d. 2010), an academic, historian, and the father of Huw Edwards, the BBC newsreader, was born and raised in Aberarth.
- Michael Geraint Robinson (b. 1962), physicist and engineer, is best known for his contribution to 3D cinema; he is an inventor on over 100 US patents relating to optical engineering and display technology. He was born and raised in Aberarth.
- Cynan Jones (b. 1975), award-winning author, is a resident of Aberarth.