This is a list of seasons played by FC Basel in Swiss and European football, from the club's founding in 1893 to the present.
It details FC Basel's record in each major competition entered including different divisions of the Swiss Football League, the Swiss Cup, the Swiss League Cup, the Inter-Cities Fairs Cup, and various UEFA competitions.
From its inception in the 1897–98 season to the 1932–33 season, the Swiss Championship (known originally as "Serie A", then "1st League", then "Nationalliga") consisted of teams playing in regional groups, followed by either a play-off match of the top 2 teams, or a championship play-off group involving the top several teams.
However, it was not until the 1944–45 season that the 2nd division of Swiss football was similarly organised, with the adoption of the names "Nationalliga A" and "Nationalliga B" for the top 2 divisions.
†Text in bold italics indicates FC Basel was promoted in addition to being Champion of the division.