The 2009–10 Swiss Challenge League was the seventh season of the Swiss Challenge League, the second tier of the Swiss football league pyramid. It began on 24 July 2009 and ended on 15 May 2010. The champions of this season, FC Thun, earned promotion to the 2010–11 Super League. The bottom two teams, FC Le Mont and FC Gossau, were relegated to the 1. Liga.

Teams

League table

Promotion/relegation play-offs

AC Bellinzona as 9th-placed team of the 2009–10 Super League played a two-legged play-off against Challenge League runners-up AC Lugano for a spot in the 2010–11 Super League. ''Bellinzona won 2–1 on aggregate and remain in the Swiss Super League. Lugano remain in the Swiss Challenge League.''

Top goal scorers