2009–10 Swiss 1. Liga

The '''2009–10 Swiss 1. Liga''' was the 78th season of this league and at this time the third tier of the Swiss football league system, the highest level of amateur football.

Format
The 1. Liga in the 2010–11 season was divided into three regional groups, each with 16 teams. Within each group, the teams would play a double round-robin to decide their positions in the league. The three groups winners and three runners-up, together with the two best third placed teams, then contested a play-off for the two promotion slots. The last placed two teams in each group would be relegated.

Qualifying Round
YF Juventus win 7–2 on aggregate.

Rapperswil-Jona win 8–2 on aggregate.

Delémont win 5–2 on aggregate.

Chiasso win 3–1 on aggregate.

Final round
Delémont win 5–3 on aggregate and achieve peomotion.

Chiasso win 3–0 on aggregate and achieve peomotion.

Chiasso are declaired 1. Liga champions.

Play-out against relegation
''FC Emmenbrücke is relegated to the 2. Liga Interregional.''