1999–2000 Swiss 1. Liga

The '''1999–2000 Swiss 1. Liga''' was the 68th 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
The Swiss Football Association (SFV-ASF) were changing the format of the Swiss football league system to the beginning of the following season. Up until and including this season, there were 56 clubs in the 1. Liga, divided into four groups of 14 teams. This was to be reduced to 48 teams and would be divided new into just three groups of 16 teams. These would then also include the best youth teams of the professional clubs from the Super League and the Challenge League. The Swiss youth U-20 championship was to be despanded, these teams would then be called U-21 and would be eligible to play in the third tier or fourth tier. The four top teams in this last U-20 championship would advance to the new 1. Liga. This all meant that the number of relegations this season was increased to twelve.

In the 1999–2000 season, the 1. Liga clubs were 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. The four group winners and the four runners-up then contested a play-off for the two promotion slots. The three last placed teams in each group were directly relegated to the newly named 2. Liga Interregional (fourth tier).

Decider
Due the fact that the club FC Bex had infrastructural deficiencies, they were not eligible to enter the play-offs for promotion to the Nationalliga B, this right was passed down to the third placed club in the division. Because the teams from Naters and Meyrin ended the season level on points they had to play a league positions decider. The match was played on a neutral ground and it took place on May 24, 2000, in Martigny.

 Meyrin win the decider and advance to play-offs.

Promotion play-off
From group 1 the group champions Chênois and decider match winners Meyrin, from group 2 the group winners Wangen b.O. and runners-up Wohlen, from group 3 champions Locarno and runners up Zug 94 played together with group 4 winners Vaduz and runners-up Red Star played in the qualification round of the play-offs. The winners here would advance to the finals. The two final winners would be promoted to the Nationalliga B.

Qualification round
 Wangen b.O. win 5–2 on aggregate and continue to the finals.

 Locarno win 4–1 on aggregate and continue to the finals.

 4–4 on aggregate, Zug 94 win on away goals and continue to the finals.

 2–2 on aggregate, Wohlen win on away goals and continue to the finals.

Final round
 Locarno win 6–4 on aggregate and are promoted to Nationalliga B.

 Wangen b.O. win 3–2 on aggregate and are promoted to Nationalliga B.

Summary
Group 1, group winners were Chênois, group 2 winners were Wangen b.O., group 3 winners were Locarno and group 4 winners were Vaduz. In the promotion play-offs Locarno and Wangen b.O. achieved promotion. Relegated were, from group 1: Renes, Visp and Signal, from group 2: Bümpliz, Stade Payerne and Lyss and from group 3: Küsnacht, Ascona and Cham. Finally from group 4: Wülflingen, Frauenfeld and Eschen/Mauren also suffered relegation.

The remaining teams in the division would be joined by Stade Nyonnais and FC Schaffhausen who suffered relegation from the Nationalliga B this season. They would also be joined by the four youth teams Servette U-21, Grasshopper Club U-21, St. Gallen U-21 and Lausanne-Sport U-21.