The signing was officially revealed by the MLS team on Saturday evening, ahead of a presentation on Sunday.
Former Barcelona striker Messi was available after his contract with French champions Paris Saint-Germain expired.
Barcelona were interested in re-signing Messi, but an offer did not materialise due to LaLiga’s financial fair play rules.
There was also interest from Saudi Arabia, where Cristiano Ronaldo, Karim Benzema, and N’Golo Kante currently play, but Messi chose to join Inter Miami, which joined the MLS in 2020 after being created two years before.
“I’m very excited to start this next step in my career with Inter Miami and in the United States,” Messi stated.
“This is a fantastic opportunity, and we will continue to build this beautiful project together.” The aim is to work together to attain the goals we establish, and I’m excited to get started here in my new home.”