1990–91 Swiss 1. Liga

The '''1990–91 Swiss 1. Liga''' was the 59th season of this league since its creation in 1931. At this time, the 1. Liga was the third tier of the Swiss football league system and it was the highest level of amateur football.

Format
There were 56 clubs in the 1. Liga, divided into four regional groups, each with 14 teams. Within each group, the teams would play a double round-robin to decide their league position. Two points were awarded for a win. The four group winners and the four runners-up then contested a play-off for the three promotion slots. The two last placed teams in each group were directly relegated to the 2. Liga (fourth tier). The four third-last placed teams would compete a play-out against the ninth relegation spot.

Decider for second place
The decider was played on 21 May in Montreux

 FC Châtel-Saint-Denis win and advance to play-offs.

Decider for twelfth place
The decider was played on 21 May in Renens

'' Concordia/Folgore Lausanne win and advance to play-outs. Vevey Sports are relegation to 2. Liga Interregional''

Decider for second place
The decider was played on 21 May 1991 at the Stadion Schlottermilch in Sursee

 FC Pratteln win and advance to play-offs.

Decider for twelfth place
The decider was played on 21 May in Altstetten (Zürich)

'' SC Veltheim win and advance to play-outs. FC Einsiedeln are relegation to 2. Liga Interregional''

Qualification round
 FC Brüttisellen win 3–2 on aggregate and continue to the finals.

 SC Brühl win 1–0 on aggregate and continue to the finals.

 SR Delémont win 8–2 on aggregate and continue to the finals.

 FC Châtel-Saint-Denis win 5–2 on aggregate and continue to the finals.

Final round
'' FC Châtel-Saint-Denis win 2–1 on aggregate and are promoted to 1991–92 Nationalliga B. ''

'' SR Delémont win 8–1 on aggregate and are promoted to 1991–92 Nationalliga B. ''

Play-off for third place
'' FC Brüttisellen win after penalty shoot-out and are promoted to 1991–92 Nationalliga B. ''

First round
'' Concordia/Folgore Lausanne win after penalty shoot-out. FC Beauregard Fribourg continue to the final.''

'' FC Suhr win after penalty shoot-out. SC Veltheim continue to the final.''

Final round
'' SC Veltheim win 4–3 on aggregate. FC Beauregard Fribourg are relegated to 2. Liga. ''

Further in Swiss football

 * 1990–91 Nationalliga A
 * 1990–91 Nationalliga B
 * 1990–91 Swiss Cup