| 그리스 페이라이오스 / UEFA RANKING 25위|
Olympiacos F.C. (Greek: ΠΑΕ Ολυμπιακός), also known simply as Olympiacos, Olympiacos Piraeus or with its full name Olympiacos C.F.P. (Greek: Oλυμπιακός Σύνδεσμος Φιλάθλων Πειραιώς, transliterated "Olympiakós Sýndesmos Filáthlo̱n Peiraió̱s"), Olympiacos Club of Fans of Piraeus, is a Greek professional football club, part of the major multi-sport club Olympiacos CFP, based in Piraeus.
Olympiacos is the most successful club in Greek football history, having won 41 Greek League titles, 26 Greek Cups, 16 Doubles and 4 Greek Super Cups, with a total of 71 national titles. Olympiacos' dominating success can be further evidenced by the fact that all the other Greek clubs have won a combined total of 37 League titles. Olympiacos also holds the record for the most consecutive Greek League titles, as they are the only team to have won 7 consecutive championships (1997–2003), having broken their own previous record of 6 (1954–1959). In addition, it is one of three clubs to have never been relegated from the top flight of Greek football; in European competitions, they have reached the quarter-finals twice, in the 1998–99 UEFA Champions League and the 1992–93 European Cup Winners' Cup. Olympiacos is also one of the founding members of the European Club Association.
Olympiacos' home ground is the Karaiskakis Stadium in Piraeus. The club is the most popular Greek club with around two and a half million fans inside Greece and millions of others in the Greek communities all over the world. Olympiacos was placed ninth on the 2006 list of clubs with the largest number of paying members, with 83,000 registered members as of April 2006. In 2014, that figure increased and the team boasts 98,000 registered members. They share a great and long-standing rivalry with Panathinaikos, with whom they contest the derby of the eternal enemies.