"Agents of the national police have arrested Djordje Prelic in Barcelona," the police said.
"He was detained at an ordinary control showing a Czech Republic passport with a false identity."
A police spokesman said the case would pass to the Spanish courts to decide on a possible extradition.
Prelic, one of four ringleaders in a group of 14 Partizan Belgrade fans convicted in Serbia in 2011, was sentenced to 35 years in prison but the punishment was later reduced to 15 years.
He was tried in absentia because he was on the run.
In the hours leading up to the game in Belgrade in September 2009, Toulouse fan Brice Taton was clubbed with bats, iron bars and flares before being thrown off a wall. He died in hospital 12 days later.
"On February 26, Prelic was identified in Barcelona at an ordinary control and he showed a Czech passport that made the agents suspicious," the police statement continued.
"The pertinent checks were made and it was found he was a Serbian, and that the identity on the passport was false.
"This morning, his true identity was confirmed, and that there was an international arrest warrant issued from his country."