| 2005–06 Challenge Cup | |
| Country: | Scotland |
| Num Teams: | 30 |
| Defending Champions: | Falkirk |
| Champions: | St Mirren |
| Runner-Up: | Hamilton Academical |
| Matches: | 29 |
| Goals: | 88 |
| Prevseason: | 2004–05 |
| Nextseason: | 2006–07 |
The 2005–06 Scottish Challenge Cup was the 15th season of the competition, competed for by all 30 members of the Scottish Football League. The defending champions were Falkirk, who defeated Ross County 2–1 in the 2004 final. Falkirk did not compete in the tournament after being promoted to the Scottish Premier League.
The final was played on 6 November 2005 and was won by St Mirren who defeated Hamilton Academical 2–1 in the final at Excelsior Stadium in Airdrie.
| Round | First match date | Fixtures | width=100 | Clubs | ||
|---|---|---|---|---|---|---|
| align=left | First round | align=left | Sat/Sun 30/31 July 2005 | 14 | 30 → 16 | |
| align=left | Second round | align=left | Tue/Wed 30/31 August 2005 | 8 | 16 → 8 | |
| align=left | Quarter-finals | align=left | Tue/Wed 13/14 September 2005 | 4 | 8 → 4 | |
| align=left | Semi-finals | align=left | Tuesday 27 September 2005 | 2 | 4 → 2 | |
| align=left | align=left | Sunday 6 November 2005 | 1 | 2 → 1 |
Airdrie United and Dumbarton received random byes into the second roundSource: ESPN Soccernet
Source: ESPN Soccernet
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See main article: 2005 Scottish Challenge Cup Final.