Bethesda is a town in Gwynedd, traditional county of Caernarfonshire, north Wales, lying on the River Ogwen and the A5 road in Snowdonia at . The town grew around the slate and stone quarrying industry, and was the site of a famous three-year strike led by the North Wales Quarrymen's Union from 1900. Although the town does have some industrial employment, many residents commute the short distance to Bangor for work.

The architecture and layout of the town is utilitarian. Most of the buildings are constructed of stone with slate roofs. Some are constructed wholly of slate blocks although such buildings tend to suffer from damp and structural slippage because the very flat and smooth surfaces of slate do not bind well to mortar. Most of the town is to the east and north east of the A5 road with housing packed onto the hill-side in irregular rows. The upper parts of Carneddi, Cilfodan and Tany y Foel owe more to stone quarrying on the nearby hills rather than slate quarrying that supported the lower end of the town. At the eastern limits, the town is bounded by the rising land of the Carneddau mountains which form some of the more remote landscapes of Snowdonia.

Bethesda is noted for the number of Chapels (see. 1904-1905 Welsh Revival) and Pubs in the town.

Bethesda is the home of the Super Furry Animals.