He becomes the club's second summer signing and arrives to shore up a defence that lost both Matías Moreno and Alan Matturro, regular starters under Luís Castro last season.
Mandi, who turns 35 in October, joins as a free agent after his contract at Lille expired at the end of last season. Born in Châlons-en-Champagne, France, he came through the Stade Reims academy before making his name in Spanish football with Betis, where he spent five seasons and played in the Europa League.
He then moved to Villarreal on a free transfer in 2021, featuring in the Champions League and the UEFA Super Cup across three seasons, before a spell at Lille in Ligue 1.
This will be Mandi's third stint in LaLiga, and he arrives with significant pedigree: 207 appearances in the Spanish top flight, plus seven Champions League and 22 Europa League outings. He has also been a mainstay for Algeria, starting regularly during this summer's World Cup before their run ended in the round of 32 against Switzerland.
The move represents a reunion with Spanish football for a defender who has rarely been short of admirers. Real Betis fans still remember his consistency across five seasons in green and white, while at Villarreal he added continental pedigree to his résumé under a succession of coaches.
His experience of European nights, both at club level and on the biggest international stage with Algeria, is exactly the profile Levante were seeking as they look to build a more settled defensive unit than the one that endured such a nervy run-in last term.
Levante's official statement read: "Levante UD and Aïssa Mandi have reached an agreement for the Algerian international defender to become a new granota player and strengthen the club's back line until June 2028."
The centre-back will undergo a medical in the coming days before joining up with Luís Castro's squad in the second week of pre-season training at the Ciudad Deportiva in Buñol. Levante will be hoping Mandi's experience helps stabilise a defence in need of leadership after last season's dramatic late survival battle in LaLiga.
With Moreno and Matturro both having moved on, Luís Castro had made central defensive reinforcement one of his priorities heading into the transfer window, and Mandi's arrival gives the Valencia-based club a proven, tournament-tested option to build around as they prepare for another top-flight campaign.