Olympiakos have sacked coach Michel, the Greek club have announced on their website.
The move comes ahead of Wednesday's Greek Cup clash against Fostiras, where Olympiakos will look to record a sixth successive victory in all competitions.
Former Spain and Real Madrid midfielder Michel, who took charge in 2013 and led the club to back-to-back Superleague titles as well as winning the Cup in his first season, leaves with Olympiakos second in the Super League standings, a point behind leaders PAOK, and still in European competition.
Olympiakos had started the season in the Champions League but narrowly failed to get out of Group A, finishing one point behind second-placed Juventus, and will now face Dnipro in the last 32 of the Europa League.
A statement on the club's website read: "Olympiakos announces the end of its collaboration with coach Michel Gonzalez.
"The whole Olympiakos family thank coach Michel for his contribution to the club and wish him every success in his career."
Before taking over at the Karaiskakis Stadium, the 51-year-old Michel coached Sevilla, Getafe, Rayo Vallecano and Real Madrid B in his homeland.