The Atocha massacre occurs in Madrid during the Spanish transition to democracy.

The 1977 Atocha massacre was an attack by right-wing extremists in the center of Madrid on 24 January 1977, which saw the assassination of five labor activists from the Communist Party of Spain (PCE) and the workers' federation Comisiones Obreras (CC.OO). The act occurred within the wider context of far-right reaction to Spain's transition to constitutional democracy following the death of dictator Francisco Franco. Intended to provoke a violent left-wing response that would provide legitimacy for a subsequent right-wing counter coup d'état, the massacre had an immediate opposite effect, generating mass popular revulsion of the far-right and accelerating the legalization of the long-banned Communist Party.