Sociedad Deportiva is a Spanish football club based in Eibar, Gipuzkoa, in the autonomous Basque Country. It was formed in 1940 by the merger of Deportivo Gallo and Unión Deportiva Eibarresa. The club was originally known as Eibar Futbol Club. Originally an irregular team, it was not until the 1943–44 season that it was reorganised into a more full-time unit.
SD Eibar is a fan-owned club, with more than 10,000 shareholders from 69 countries all over the world.
It is the only football club that has an ISO 9001:2008 Quality management systems certificate, which deals with the requirements that organisations wishing to meet the standard must fulfill.
