The 2009–10 season was Olympiacos' 51st consecutive season in the Superleague Greece. Olympiacos finished 2nd in the regural season of the Greek SuperLeague and ranked last at the play-off games, resulting in a 5th place at the League,the worst position of team's recent seasons. Olympiacos also participated in UEFA Champions League 09-10, and managed to qualify to the knock-stage (round of 16). They lost twice from French side Bordeaux, 3-1 on aggregate.

This season was the last season with Sokratis Kokkalis as chairman of the club. The 5th league position as well as the team's low level of spectacle created a disappointing atmosphere, resulting in Kokkalis's decision to leave the club after two decades of constant presence.

Note: Flags indicate national team as defined under FIFA eligibility rules. Players may hold more than one non-FIFA nationality.

EU Nationals

Non-EU Nationals

As on: 21 August 2009, Source: Olympiacos F.C. U21 Team Note: Flags indicate national team as defined under FIFA eligibility rules. Players may hold more than one non-FIFA nationality.

In: Note: Flags indicate national team as defined under FIFA eligibility rules. Players may hold more than one non-FIFA nationality.

Out: Note: Flags indicate national team as defined under FIFA eligibility rules. Players may hold more than one non-FIFA nationality.

Total income: €5 million

...
Wikipedia