The 2005–06 Swiss Challenge League was the third season of the Swiss Challenge League, the second tier of the Swiss football league pyramid. It began on 15 July 2005 and ended on 13 May 2006. The champions of this season, FC Luzern, earned promotion to the 2006–07 Super League. The runners-up FC Sion won the promotion/relegation playoff against the 9th-placed team of the 2005–06 Super League, Neuchâtel Xamax. The bottom tho teams, FC Baden and FC Meyrin, were relegated to the 1. Liga.