| Club: | Celtic |
| Season: | 2005–06 |
| Manager: | Gordon Strachan |
| Chairman: | Brian Quinn |
| Stdtitle: | Ground |
| Stadium: | Celtic Park Glasgow, Scotland (Capacity: 60,355) |
| League: | Scottish Premier League |
| League Result: | 1st |
| Cup1: | Scottish Cup |
| Cup1 Result: | Third Round |
| Cup2: | Scottish League Cup |
| Cup2 Result: | Winners |
| Cup3: | Champions League |
| Cup3 Result: | Second qualifying round |
| League Topscorer: | John Hartson (18) |
| Season Topscorer: | Maciej Żurawski John Hartson (20 each) |
| Pattern La1: | _celtic0507h |
| Pattern B1: | _celtic0507h |
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| Pattern La2: | _celtic0506a |
| Pattern B2: | _celtic0506a |
| Pattern Ra2: | _celtic0506a |
| Pattern Sh2: | _celtic0506a |
| Pattern So2: | _celtic0506a |
| Leftarm2: | 008000 |
| Body2: | 008000 |
| Rightarm2: | 008000 |
| Shorts2: | 008000 |
| Socks2: | 008000 |
| Pattern La3: | _celtic0506t |
| Pattern B3: | _celtic0506t |
| Pattern Ra3: | _celtic0506t |
| Pattern Sh3: | _celtic0506t |
| Pattern So3: | _celtic0506tl |
| Leftarm3: | 333333 |
| Body3: | 333333 |
| Rightarm3: | 333333 |
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| Prevseason: | 2004–05 |
| Nextseason: | 2006–07 |
Celtic started the season 2005–06 looking to win the Scottish Premier League trophy and retain the Scottish Cup. They competed in the Scottish League Cup, and entered the Champions League at the qualification stage.
Celtic were knocked out of the Scottish Cup in the third round by Clyde, losing 2–1. They won the Scottish League Cup with a comfortable 3–0 victory over Dunfermline on 19 March 2006, while the league was regained after a 1–0 win over Hearts. Rival managers were quick to praise the manner in which Celtic had regained the SPL title.[1]
See main article: 2005–06 Scottish Premier League.
See main article: 2005–06 UEFA Champions League.
See main article: 2005–06 Scottish League Cup.
See main article: 2005–06 Scottish Cup.
List of squad players, including number of appearances by competition|}
| Player | Scottish Premier League | Scottish League Cup | Scottish Cup | UEFA Champions League | Total | ||
|---|---|---|---|---|---|---|---|
| align=center rowspan=2 | 1 |  Maciej Żurawski | 16 | 3 | 1 | 0 | 20 |
| John Hartson | 18 | 1 | 0 | 1 | 20 | ||
| align=center rowspan=1 | 2 | Shaun Maloney | 13 | 3 | 0 | 0 | 16 |
| align=center rowspan=1 | 3 |  Stiliyan Petrov | 10 | 0 | 0 | 0 | 10 |
| align=center rowspan=1 | 4 | Stephen McManus | 7 | 0 | 0 | 1 | 8 |
| align=center rowspan=1 | 5 | Craig Beattie | 6 | 0 | 0 | 1 | 7 |
| align=center rowspan=1 | 6 |  Shunsuke Nakamura | 6 | 0 | 0 | 0 | 6 |
| align=center rowspan=1 | 7 | Aiden McGeady | 4 | 0 | 0 | 0 | 4 |
| align=center rowspan=1 | 8 | Alan Thompson | 2 | 0 | 0 | 1 | 3 |
| align=center rowspan=3 | 9 | Chris Sutton | 2 | 0 | 0 | 0 | 2 |
| Stephen Pearson | 2 | 0 | 0 | 0 | 2 | ||
| Dion Dublin | 1 | 1 | 0 | 0 | 2 | ||
| align=center rowspan=5 | 9 |  Bobo Balde | 1 | 0 | 0 | 0 | 1 |
| Paul Telfer | 1 | 0 | 0 | 0 | 1 | ||
| Roy Keane | 1 | 0 | 0 | 0 | 1 | ||
| Neil Lennon | 1 | 0 | 0 | 0 | 1 | ||
 Stanislav Varga | 1 | 0 | 0 | 0 | 1 |
| £500,000 | ||
| Free | ||
| Loan | ||
| £200,000 | ||
| £1.5 million | ||
| £2.5 million | ||
| £2.5 million | ||
| £900,000 | ||
| Free | ||
| End of loan | ||
| Free | ||
| Free | ||
| Free | ||
| Free | ||
| Free | ||
| Free | ||
| Free | ||
| Free | ||
| Free | ||
| Chelsea | Free | |
Total spending: £7.6 million
Total income: £0