| Competition: | 1. Liga |
| Season: | 1989–90 |
| Winners: | Group 1: Urania Genève Sport Group 2: FC Thun Group 3: SC Kriens Group 4: SC Brühl |
| Promoted: | Urania Genève Sport SC Burgdorf SC Kriens |
| Relegated: | Group 1: FC Stade Nyonnais FC Bramois Group 2: FC Biel-Bienne FC Boudry Group 3: FC Muri SC Derendingen Group 4: FC Vaduz FC Landquart FC Wohlen |
| Matches: | 4 times 182 plus 14 play-offs and 4 play-outs |
| Prevseason: | 1988–89 |
| Nextseason: | 1990–91 |
The 1989–90 Swiss 1. Liga was the 58th 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.
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.
| Club | Canton | Stadium | Capacity |
|---|---|---|---|
| FC Aigle[1] | Vaud | Les Glariers | |
| FC Beauregard Fribourg[2] | Fribourg | Guintzet | |
| FC Bramois[3] | Valais | Stade du Bois-de-la-Borgne/Glareys | |
| FC Châtel-Saint-Denis[4] | Fribourg | Stade du Lussy - Châtel-St-Denis | |
| FC Collex-Bossy[5] | Geneva | Stade Marc Burdet | |
| Concordia/Folgore Lausanne[6] | Vaud | Centre Sportif de la Tuilière | |
| FC Echallens | Vaud | Sportplatz 3 Sapins | |
| FC Fully[7] | Valais | Stade de Charnot | |
| FC Monthey | Valais | Stade Philippe Pottier | |
| FC Raron[8] | Valais | Sportplatz Rhoneglut | |
| FC Renens[9] | Waadt | Zone sportive du Censuy | |
| FC Stade Nyonnais | Vaud | Stade de Colovray | |
| Urania Genève Sport | Geneva | Stade de Frontenex | |
| Vevey Sports | Vaud | Stade de Copet | |
| Club | Canton | Stadium | Capacity |
|---|---|---|---|
| FC Bern | Bern | Stadion Neufeld | |
| FC Biel-Bienne | Bern | Stadion Gurzelen | |
| FC Breitenbach[10] | Solothurn | Grien | |
| FC Boudry[11] | Neuchâtel | Stade des Buchilles | |
| FC Colombier | Neuchâtel | Stade des Chézards | |
| SR Delémont | Jura | La Blancherie | |
| FC Domdidier[12] | Fribourg | Terrains de football - Domdidier | |
| FC Laufen | Basel-Country | Sportplatz Nau | |
| FC Lerchenfeld[13] | canton of Bern | Sportanlagen Waldeck | |
| FC Le Locle[14] | Neuchâtel | Installation sportive - Jeanneret | |
| SV Lyss[15] | Bern | Sportzentrum Grien | |
| FC Moutier[16] | Bern | Stade de Chalière | |
| FC Münsingen | Bern | Sportanlage Sandreutenen | |
| FC Thun | Bern | Stadion Lachen | |
| Club | Canton | Stadium | Capacity |
|---|---|---|---|
| FC Ascona[17] | Ticino | Stadio Comunale Ascona | |
| SC Burgdorf[18] | canton of Bern | Stadion Neumatt | |
| SC Buochs | Nidwalden | Stadion Seefeld | |
| SC Derendingen[19] | Solothurn | Heidenegg | |
| FC Klus-Balsthal |