The 32-year-old will arrive at the club at the conclusion of his current contract with Dutch champions PSV Eindhoven.
Born in General José de San Martín, in northern Argentina, Benítez made his breakthrough with Primera División club Quilmes in Buenos Aires, before spending six seasons with Nice in Ligue 1.
The ‘keeper has made 134 appearances over three seasons for PSV, winning back-to-back Eredivisie titles (in 2024 and 2025); the KNVB Cup (in 2023); and two Johan Cruyff Shields (in 2022 and 2023), all-the-while keeping 43 clean sheets in all competitions.
Benítez has also impressed in continental and international football, featuring 27 times for PSV in the UEFA Champions League. First called up in June 2023, he has been selected in 10 of Argentina’s last 12 international squads, winning his first cap in a 3-1 win over Costa Rica in March of last year.
Chairman Steve Parish said: “Walter is an excellent addition to our squad, bringing further quality, experience and competition to our goalkeeping department alongside Dean and Remi.
“We look forward to welcoming Walter to South London next month as we continue our preparations towards what promises to be a busy season, competing on multiple fronts, in 2025/26.”