The Spanish champions disclosed the signing of the French striker by posting videos of the former Real Sociedad forward on their social media handles.
"The player will sign a contract with his new club for the next five seasons, through to 30 June 2024, with a buyout clause of 800 million euros," Barca said in a statement.
The securing of the player’s services will now end the dispute between Griezmann and Atletico Madrid as he was near to be fined by the club, having missed their pre-season tour.
Griezmann in last year June rejected to join the Catalan giants when the side sent a bid to bring him to the Camp Nou.
But the France World Cup winner is now a player of the side that have already signed Ajax’s midfielder Frenkie de Jong and Valencia’s shot-stopper Neto.
The 28-year-old becomes the world's sixth most expensive signing after Neymar, Kylian Mbappe, Philippe Coutinho, Joao Felix and Ousmane Dembele.
Griezmann, who was born in France has spent his football career in Spain having joined the Wanda Metropolitano club from Real Sociedad in 2014 for a fee reported to be in the region of €30 million (£24 million).
In his last season with Atletico Madrid, Griezmann netted 21 times in all competitions for the side as he bagged 15 goals in thirty-seven LaLiga games with nine assists, having won the Europa League, UEFA Super Cup and Supercopa de Espana with the club.
