The Eredivisie giants will have the option to make Ocampos’ stay permanent for a reported €20million at the end of the season.
Ocampos made exactly 100 league appearances for Sevilla after moving to Spain in 2019 from Marseille, though his best form came in his first season at the Estadio Ramon Sanchez Pizjuan, when he scored 17 goals in all competitions.
The 28-year-old has 10 senior caps for Argentina, the most recent of which came earlier this year.
The addition of Ocampos will come as a relief to the Dutch champions, who have seen several key players leave during the transfer window.
Antony’s departure follows those of Lisandro Martinez, Sebastien Haller, Ryan Gravenberch, Noussair Mazraoui, Andre Onana and Nicolas Tagliafico.
And the exodus could be set to continue amid reports Chelsea have made a £43m (€49.7m) bid for midfielder Edson Alvarez ahead of Thursday’s transfer deadline.
Chelsea have already spent big in their first transfer window under the ownership of Todd Boehly and Clearlake Capital, but reports suggest head coach Thomas Tuchel is keen to bring the 24-year-old in to ease a growing injury crisis at Stamford Bridge.
Fellow Ajax midfielder Mohammed Kudus, meanwhile, is reportedly being targeted by Frank Lampard’s Everton.