This study examines how left-wing ideology is articulated, displayed and enacted among organized groups of football fans in Spain. The left-wing political space in Spanish football fan culture is occupied by multiple autonomous but often interconnected points of organizational and activist activity characterized by ideological flexibility, heterogeneous identities and interests, and a diffuse message, and whose solidarity is based on a sense of shared struggle. Solidarity and identification among left-wing fan groups is built through the contestation of three issues: neo-fascism, racism and the increasing commercialization of football. The political beliefs and actions of left-wing fan groups in Catalonia, the Basque Country and Galicia are further informed by peripheral nationalisms and the struggle for the revival of the historic communities. It is illustrated how left-wing fans promote and engage in collective social action at the local, national and transnational levels.