The 28-year-old, a World Cup victor with France last summer, has signed a contract that will run until 2024, the Catalan club said.
Barcelona, which won La Liga last season by nine points, has strengthened itself at the expense of second-placed Atletico Madrid by signing its leading scorer in each of the last five campaigns.More news: This is the Mi A3, Xiaomi's new pure Android smartphone
The drama may not end here, however.
Griezmann has always been expected to join Barcelona since his impending departure from Atletico was announced in May.
He becomes Barcelona's third signing of the summer following their £60m capture of Frankie de Jong from Ajax while right-back Emerson joined from Atletico Mineiro in Brazil.
"Atletico de Madrid considers that the deposited amount is insufficient to cover his buyout clause, since it is obvious that the agreement between the player and FC Barcelona was closed before the clause was reduced from €200 million to €120 million".More news: United Airlines cancels another 5,000 Boeing 737 Max flights
Before joining Atletico Madrid in July 2014, Griezmann had played for another Spanish club, Real Sociedad.
"They've made a great signing", Cerezo confessed.
It is likely Atletico's failure to win the UEFA Champions League last season, despite enjoying a comfortable first leg position against favorites Juventus in last season's round of 16, was a key factor in Griezmann's decision.More news: Buy this MacBook Pro Right Now!