The court voted 8 to 3 against the Catalan ban, finding that lawmakers from the region could not prohibit a practice that the justices said was enshrined in the cultural patrimony of the Spanish state.
In its ruling, the court said that regional politicians in Catalonia and elsewhere could regulate bullfighting and introduce specific measures, but that they could not ban it outright. The decision is not necessarily the final word, but any appeal against the constitutional court's decision would also most likely have to be made before European courts.
Catalan politicians vowed on Thursday to never allow bullfights to return to Catalonia, without even mentioning a possible appeal.
The Catalan regional Parliament voted in 2010 to ban bullfighting, on the grounds that it represented unjustified cruelty to animals.
The ban was welcomed by animal rights activists as their most significant victory in Spain, and they were outraged by the reversal on Thursday.