Following the private ceremony, the couple appeared happy and relaxed as they walked a red carpet before hundreds of media at a hotel and casino complex, Roccuzzo donning a tight, mermaid-style gown by Spanish designer Rosa Clara.
Shakira and her husband, Messi's teammate Gerard Pique, flew in to join the 260 guests including numerous footballers such as Messi's Barcelona strike partners Neymar and Luis Suarez.
Argentine media called it the "wedding of the century" for Rosario, the gritty northern port city where Messi, 30, and his bride, 29, met when the player was nine years old.
Former Barca and current Chelsea star Cesc Fabregas was in attendance, along with Argentina and Manchester City striker Sergio Aguero.
The party was to be a respite for Messi from his legal woes. A Spanish court last month rejected his appeal against a conviction for tax fraud.
Brunette bride Roccuzzo wore a white, curve-hugging dress with a deep sweetheart neckline and embroidered straps by Rosa Clara- a Spanish designer who has dressed actress Eva Longoria and Spain's Queen Letizia.
The wedding was held at 2200 GMT in the City Center casino, which stands right next to a crime-ridden slum run by drug gangs.
The civil wedding ceremony and party were all slated to take place inside the venue, and the guests will be lodged there too.
The feast will reportedly feature Argentine delicacies such as roast gizzards.
Uruguayan pop bands Rombai and Marama plus singer Karina, Aguero's wife, will perform at the reception.
There were also rumors that there would be singing by Shakira, the Colombian diva famous for "Hips Don't Lie" and "Whenever, Wherever."
Shakira had recently denied rumors that she would miss the wedding due to a quarrel with Roccuzzo.
Messi and Roccuzzo live in Barcelona where he plays, but still return regularly to Rosario for vacations.
He moved to Spain when he was 13 to join FC Barcelona, but the couple kept in touch.
Messi has gone on to win the top Ballon d'Or award five times. He is widely regarded as the world's best footballer.
But various old friends of the couple in their home city said the bride and groom are humble folk who have never forgotten where they come from.
"They are the love of each other's lives," Messi's childhood friend Diego Vallejos told AFP.
Instead of wedding presents, they have asked for donations to a children's charity.
'LEO AND ANTO'
The couple have reportedly spent the past two weeks in Rosario with family, but have kept out of sight of the reporters who have invaded the city.
Rumors circulated of bachelor and bachelorette parties, but the only evidence that emerged was a photo, posted by ex-Barca goalkeeper Jose Pinto, of Messi enjoying a barbecue with a few friends.
Some friends of Roccuzzo have shared pictures of her relaxing with relatives.
On the eve of the wedding, a festive atmosphere reigned in the Las Heras neighborhood where Messi grew up.
"We will celebrate," said Damian Lugoni, 27, a local sausage sandwich vendor.
"I wish good luck to Leo and Anto, who is just as simple and nice as him."
"We are all happy for them," said Lisandro Urteaga, an artist who was called in to paint a mural of Messi in the neighborhood for the occasion.
"Let him celebrate the way someone like him deserves. He is a real example as a human being - although when he plays football he doesn't seem to be from this planet."