About 250 guests attended the wedding of Messi and Antonella Roccuzzo at a luxury hotel, including Messi's Barcelona teammates Neymar, Luis Suarez and Gerard Pique, who was joined by his wife, Colombian pop star Shakira.
Argentines were abuzz over the wedding in Rosario, an agricultural hub and the country's third-largest city about 186 miles north west of Buenos Aires.
About 150 journalists were allowed to cover the event, but had no direct access to the ceremony or the party afterwards.
Onlookers gathered before the wedding near the heavily-guarded site, hoping to snap photos of the stars.
"We think it's great that Messi has come to Rosario to get married," said window cleaner Julio Sosa.
Messi, 30, grew up in a lower-middle-class neighbourhood in Rosario along with two brothers and a sister.
His bride, 29, is the cousin of a close Messi friend and the new couple have been close friends since meeting at a young age.
Messi and Ms Roccuzzo stayed in touch after he left to play football in Spain at 13 and they eventually started a romantic relationship in the late 2000s.
Ms Roccuzzo moved to Barcelona, where the couple live with their two sons, Thiago, four, and Mateo, one, but often return to their native Rosario.
"Messi could have had this wedding wherever he liked - Dubai, the moon. He can pay any plane ticket to anyone, but he chose the city that's in his heart," said Leandro Macaya.
Messi, a five-time Fifa world player of the year, has faced criticism in Argentina because he has never brought the country a major title, in contrast to his repeated successes playing for Barcelona.
But he is praised both at home and abroad for keeping his common touch.
"He was always the same and he never changed," said Diego Vallejos, a childhood friend who was invited to the wedding.
"Despite everything that he's accomplished in life, he's still the same simple kid, the skinny dude that I grew up with.
"It's hard to explain the feeling - I'm both a friend and a fan."