| 1905-06 | Elected to Football League Division Two |
| 1906-07 | Football League Division Two runner-up |
|
| Promoted to Division One |
|
| Also joined Western League Division 1A |
| 1910 | Relegated to Division Two |
| 1910-11 | F.A. Cup semi-finalists |
| 1911-12 | Football League Division Two runner-up (lost title on goal average) |
|
| Promoted to Division One |
| 1914-15 | F.A. Cup runner-up |
| 1915 | Finished in a relegation position, but reprieved when the First |
|
| Division was extended after the War |
| 1919-20 | F.A. Cup semi-finalists |
| 1924 | Relegated to Division Two (on goal average) |
| 1929-30 | Promoted to Division One |
| 1931-32 | F.A. Cup semi-finalists |
| 1939-40 | Football League programme abandoned due to outbreak of war |
| 1949-50 | F.A. Cup semi-finalists |
| 1951 | Escaped relegation on goal average |
| 1951-52 | F.A. Cup semi-finalists |
| 1954-55 | Football League Champions |
| 1958-60 | European Inter Cities Fairs Cup Quarter Finalists |
| 1962 | Relegated to Division Two |
| 1962-63 | Football League Division Two runner-up, and promoted to Division |
|
| One, on goal average |
| 1964-65 | Football League Cup Winners |
|
| F.A. Cup semi-finalists |
| 1965-66 | F.A. Cup semi-finalists |
| 1966-67 | F.A. Cup runner-up |
| 1969-70 | F.A. Cup Winners |
| 1970-71 | European Cup Winners Cup Winners |
| 1971-72 | Football League Cup runner-up |
| 1972-73 | Football League Cup semi-finalists |
| 1975 | Relegated to Division Two |
| 1976-77 | Football League Division Two runner-up |
|
| Promoted to Division One |
| 1979 | Relegated to Division Two |
| 1979-80 | Missed promotion place on goal difference |
| 1983-84 | Football League Division Two Champions (on goal difference) |
|
| Promoted to Division One |
| 1984-85 | Football League Cup semi-finalists |
| 1986-87 | Forced to compete in relegation play-offs on goal difference - |
|
| eventually relegated (SF Blackburn Rovers 0 Chelsea 2, Chelsea |
|
| 4 Blackburn Rovers 1 (Agg 6-1), F Middlesbrough 2 Chelsea 0, |
|
| Chelsea 1 Middlesbrough 0 (Agg 1-2) |
| 1988-89 | Football League Division Two Champions |
|
| Promoted to Division One |
| 1990-91 | Football League Cup semi-finalists |
| 1992-93 | Founder members of F.A. Premiership |
| 1993-94 | F.A. Cup runner-up |
| 1994-95 | European Cup Winners Cup Semi-Finalists |
| 1995-96 | F.A. Cup semi-finalists |
| 1996-97 | F.A. Cup Winners (2nd time) |
| 1997-98 | European Cup Winners Cup Winners (2nd time) |
|
| European Super Cup Winners |
|
| Football League Cup Winners (2nd time) |
| 1998-99 | European Cup Winners Cup Semi-Finalists |
| 1999-00 | F.A. Cup Winners (3rd time) |
| 2001-02 | Football League Cup semi-finalists |
|
| F.A. Cup Finalists |
| 2003-04 | F.A. Premiership runner-up |
|
| European Champions League semi-finalists |
| 2004-05 | F.A. Premership Champions |
|
| Football League Cup Winners (3rd time) |
|
| European Champions League semi-finalists |
| 2005-06 | F.A. Premiership Champions (2nd time) |
|
| F.A. Cup semi-finalists |
