— Sevilla Fútbol Club (@SevillaFC) July 20, 2020
Suso joined Sevilla initially on loan and now that Sevilla have qualified for the Champions League, they were obliged their option to sign him permanently.
The statement on the Sevilla website claims the winger has penned a five-year contract at the club.
The 26-year-old arrived at the Andalusian club in January and has made 19 appearances, scoring one goal and providing one assist.
Suso made 153 appearances at the Milanese giants, where he scored 24 goals, provided 36 assists and won an Italian Supercoppa.
The winger joined Milan in a reported €1.3m deal from Liverpool in January 2015 having spent the 2013/14 campaign in La Liga on a loan deal with Almeria.