Pop star Shakira and her husband, Messi's teammate Gerard Pique, were expected among the 260 guests, according to media and locals close to the event.
They will join old friends of the couple and footballers, including his Barcelona strike partners Neymar and Luis Suarez, in Messi's northern hometown, Rosario.
Suarez and other soccer stars were watched by curious locals as they stepped off private jets on Thursday at Rosario's airport.
- All-star guest list -
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Brunette bride Roccuzzo, 29, will wear a dress by Rosa Clara -- a Spanish designer who has dressed actress Eva Longoria and Spain's Queen Letizia.
From 2200 GMT the guests will pack into the Hotel City- Center Casino, which stands right next to a crime-ridden slum run by drug gangs.
This city of 1.2 million people is also a cradle of footballing talent, however.
"Rosario lives and breathes football. That is another reason Lionel feels so comfortable here," the city's mayor, Monica Fein, told AFP.
- Roast gizzards -
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The civil wedding ceremony and party will all take place inside the venue, and the guests will be lodged there too.
Messi, 30, has reportedly asked chefs to cook local delicacies such as "locro" stew and "empanada" pasties for the feast.
The star dish is a typical Argentine beef roast including chitterlings, gizzards and kidneys.
Uruguayan pop bands Rombai and Marama plus singer Karina, wife of Argentina footballer Sergio Aguero, will perform at the dance.
- Guards and reporters -
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Organizers say 157 journalists have been accredited to cover the bash, but have been warned they will have no access to the guests.
Security will be handled by a private team of Israeli specialists used by Messi for all his excursions.
Messi and Roccuzzo live in Barcelona where he plays, but still return regularly to Rosario on holiday.
The couple met as children. He moved to Spain when he was 13 to join FC Barcelona, but they kept in touch.