Euskotren Tranbia is the brand under which the tramway networks in the cities of Vitoria-Gasteiz and Bilbao are run. The system in Bilbao started operations in 2002, and the one in Vitoria-Gasteiz in 2008. It is one of the four commercial divisions under which Euskotren operates. The infrastructure is owned by the public entity Euskal Trenbide Sarea and tracks use 1,000 mm narrow gauge.

The Basque Country, also called the Basque Autonomous Community, is an autonomous community in northern Spain. It includes the Basque provinces of Álava, Biscay, and Gipuzkoa. It also surrounds an enclave called Treviño, which belongs to the neighboring autonomous community of Castile and León.