Porto part company with Ferreira
The club did not say who would replace him.
Ferreira joined Porto from Boavista in 2006 and led the club to three consecutive league titles and two Portuguese Cup triumphs.
The 64-year-old also took Porto beyond the Champions League group stage in all four seasons at the club.
Porto finished third in the league this season behind Benfica and Braga, missing out on a Champions League spot.