Greek champions Olympiakos on Wednesday announced the return of Spanish coach Michel after the sacking of Carlos Corberan.
Corberan was fired after a 2-1 Super League loss at Aris Thessaloniki on Sunday.
"To make the present the way we want it to be again, this can only be done with humility and hard work," Michel said.
The 59-year-old Michel won two Greek league titles and the Greek Cup during his first stint at the club from 2013 to 2015.
"We have experienced unique European evenings with him, with an Olympiakos team that played very good football and was looking one of the best teams in Europe," said Olympiakos owner Evangelos Marinakis, who is also the owner of Premier League side Nottingham Forest.
Greek media had reported that Marinakis was hoping to sign former France and Paris Saint-Germain coach Laurent Blanc but that the two sides failed to agree terms.
Corberan lasted only six weeks with Olympiakos and leaves with the club seven points adrift of early leaders Panathinaikos after five matches.
Frenchman Jose Anigo has also been named as Olympiakos' new director of football.
Anigo led Marseille to the 2004 Uefa Cup final as coach and was later their director of football.