Atxondo (Spanish: Achondo) is a municipality located in the province of Biscay, in the Basque Country, Spain.

Atxondo is part of the comarca of Durangaldea and has a population of 1,447 inhabitants as of 2007 according to the Spanish National Statistics Institute.

Until 1962, Achondo was the name for a valley where three different municipalities formed by three elizates where located; Apatamonasterio, Arrazola and Axpe, each of them with history of its own.

As a member of the ancient merindad of Durango, it had voice and right to vote in the Juntas of Guerendiaga, where it occupied the seat number eight.

In Arrasate-Mondragón the BI-634 road connects with the AP-1 highway, to Eibar (and from there to Donostia-San Sebastián and France) and to Vitoria-Gasteiz, the capital city of the province of Álava.