The 30-year-old brought an end to a nine-year stint with Real Madrid following the expiration of his contract in June, having fallen down the pecking order since Carlo Ancelotti's return to the club.
Isco departed the Spanish capital with a stacked trophy cabinet that includes three La Liga titles and five Champions League triumphs.
Capped 38 times by Spain, though his last call up was in 2019, Isco's move to Sevilla will see him reunite with former national team boss Julen Lopetegui – who also had a brief stint at Real Madrid.
Sevilla confirmed Isco would undergo medical tests on Tuesday (AEST) ahead of signing a two-year deal with the club.
The club commence their 2022-23 season at Osasuna on Friday.