The 31-year-old winger was a member of Iranian team Sepahan in the last season.
Hajsafi played for Greek football team Olympiacos in 2018.
He will join his compatriot Karim Ansarifard in AEK.
Hajsafi will wear No. 26 jersey in the Greek top-flight football club.
AEK Athens Football Club is a Greek professional football club based in Nea Filadelfeia, a suburb of Athens, Greece.