The Esteghlal Khuzestan striker has signed a three-year contract with Charleroi.
The 19-year-old player had already been linked with a move to PSV Eindhoven and Besiktas in the summer transfer window.
He represented Iran at the 2017 FIFA U-17 World Cup in India. Delfi burst onto the scene by recording two goals and one assist in the group stages of the competition.
He also showed phenomenal technical ability by also getting two penalties for the Iran U-17 national team in the three group matches.
Delfi replaced his compatriot Ali Gholizadeh, who has been sidelined due to foot injury, in the Belgian team.