Former AC Milan, Chelsea and Brazil attacker Pato had his contract with Sao Paulo mutually terminated last August and had been hoping for a return to Europe.
However, the 31-year-old will continue his career in MLS with Orlando, who fell to New England Revolution in the Eastern Conference semifinals last season.
“We are very excited to welcome Pato to Orlando. He’s a veteran player who has featured at some of the top clubs around the world and has a proven track record at the international level,” said Orlando executive vice-president of soccer operations Luiz Muzzi.
“The experience that Pato brings with him will be invaluable to the club. Pato is a high-calibre player and we’re excited to add another great target up top.”
Pato was one of the most highly rated young players in world football when he left Internacional for Milan in 2007, but his career stagnated due to injuries.
After largely unsuccessful stints at Corinthians, Sao Paulo, Chelsea and Villarreal he joined Tianjin Tianhai in the Chinese Super League and rediscovered his scoring touch with 30 goals in 47 Chinese Super League games.
He failed to maintain that form after returning to Sao Paulo in 2019 on a three-year contract and departed after dropping down the pecking order.