List of Galatasaray S.K. seasons

Galatasaray Spor Kulübü is a professional football club based in Istanbul, that competes in Süper Lig, the most senior football league in Turkey. The club was formed in 1905 as Galata-Serai Football Club and played its first friendly match on 10 November 1905. Galatasaray managed to win its first ever match, when they beat Faure Mektebi 2–0. Galatasaray played its first competitive match on 25 November 1906, when it drew 1–1 in the first week of the 1906–07 Istanbul Football League against HMS Imogene FC. Initially Galatasaray played against other local clubs in various Istanbul tournaments, but in 1959 the club became one of the founding members of Süper Lig, Turkey's first national league. Galatasaray is one of the founding members of the Turkish Super Lig in 1959 and is one of only three clubs never to have been relegated from the top level of Turkish football, the others being the archrival Fenerbahçe and Beşiktaş.

Galatasaray's most successful spell was in the 1999–2000 season, where they won not only the Süper Lig and Turkish Cup, but also the UEFA Cup by defeating English club Arsenal in the final of the latter.

The club has won the Süper Lig championship a record 23 times, the Turkish Cup a record 18 times, the Turkish Super Cup a record 15 times, the UEFA Europa League one time and the UEFA Super Cup one time. The table details the club's achievements in the early regional championships and in all national and international first-team competitions for each completed season since the club's formation in 1905.

Key
Key to league:
 * Pos = Final position
 * Pld = Matches played
 * W = Matches won
 * D = Matches drawn
 * L = Matches lost
 * GF = Goals scored
 * GA = Goals against
 * Pts = Points

Key to divisions and rounds:
 * C = Champions
 * F = Final (Runners-up)
 * SF = Semi-finals
 * QF = Quarter-finals
 * R16/R32 = Round of 16, round of 32, etc.
 * GS = Group stage
 * POR = Play-off round
 * 3QR = 3rd qualifying round
 * 5R = 5th round