A.E.K. Football Club (Greek: Αθλητική Ένωσις Κωνσταντινουπόλεως, romanized: Athlitiki Enosis Konstantinoupoleos, lit. 'Athletic Union of Constantinople'), known simply as A.E.K. (Greek: A.E.K.; ) in Greece and AEK Athens internationally, is a Greek professional football club based in Nea Filadelfeia, Attica, Greece. Established in Athens by Greek refugees from Constantinople in the wake of the Greco-Turkish War (1919–1922), AEK is one of the most successful teams in Greek football, by winning 32 national titles it is the only club to have won all the competitions organised by the Hellenic Football Federation (13 Greek Championships, 16 Greek Cups, 1 League Cup and 2 Super Cups). The club has appeared several times in European competitions (UEFA Champions League, UEFA Europa League, and the defunct UEFA Cup Winners' Cup). It is the only Greek team to have advanced to the semi-finals of the UEFA Cup (1976-77) and the quarter-finals of the UEFA Cup Winners' Cup twice (1996-97 and 1997-98). AEK was also the first Greek team to reach the quarter-finals of the European Cup (1968–69) and to qualify for the group stage of the UEFA Champions League (1994-95).

A.E.K Basketball Club (Greek: Αθλητική Ένωσις Κωνσταντινουπόλεως, Athlitiki Enosis Constantinoupoleos, means Athletic Union of Constantinople), also known simply as AEK BC (Greek: Α.Ε.Κ. Κ.Α.Ε.) or AEK, known in European competitions as AEK Athens, is a Greek professional sports basketball club based in Athens, Greece, part of the major multi-sport club A.E.K.. The club was established in Athens in 1924 by Greek refugees from Constantinople in the wake of the Greco-Turkish War (1919–1922). AEK was the first-ever Greek basketball team, not only to reach a European Cup Final, but also to win a European title. On April 4, 1968, AEK defeated Slavia VŠ Praha by a score of 89-82, in Athens in front of 80,000 fans. They have won the Greek Basket League 8 times (1957–58, 1962–63, 1963–64, 1964–65, 1965–66, 1967–68, 1969–70, 2001–02), and the Greek Basketball Cup 3 times (1980–81, 1999–00, 2000–01), while they have also twice won the FIBA Saporta Cup (former European Cup Winners' Cup) (1967–68 and 1999-00). They are one of the most popular Greek clubs, with millions of fans in both Greece and Cyprus, as well as in the Greek communities all over the world, mainly in Australia, the United Kingdom, and North America. Well-known players that have played with the club over the years have included: Rolando Blackman, Ricky Pierce, Danny Vranes, Ruben Patterson, Kurt Rambis, J.R. Holden, Willie Anderson, Joe Arlauckas, Anthony Bowie, Arijan Komazec, Martin Müürsepp, Clint Richardson, Bill Edwards, Victor Alexander, Claudio Coldebella, İbrahim Kutluay, Pero Antić, Carl English, Pops Mensah-Bonsu, Bane Prelević, Georgios Amerikanos, Georgios Trontzos, Vassilis Goumas, Minas Gekos, Kostas Patavoukas, Angelos Koronios, Michalis Kakiouzis, Nikos Chatzis, Jake Tsakalidis, Nikos Zisis, Nasos Galakteros, Dimos Dikoudis, Dimitris Papanikolaou, Ioannis Bourousis and Loukas Mavrokefalidis. AEK B.C. has been named as the best Greek team in all sports, at either the sports club or national team level, on three separate occasions, in 1965, 1966, and 1968, by SJA of Greece (the Sports Journalists' Association of Greece, Greek: ΠΣΑΤ).