1998–99 Swiss 1. Liga

The '''1998–1999 Swiss 1. Liga''' was the 67th 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 of 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 two last placed teams in each group were directly relegated to the 2. Liga Interregional (fourth tier). The four third-last placed teams would compete a play-out against the ninth relegation place.

Qualification round
 Winterthur win 4–0 on aggregate and continue to the finals.

 Vevey Sports win 4–2 on aggregate and continue to the finals.

 Münsingen win 3–2 on aggregate and continue to the finals.

 Bellinzona win 5–0 on aggregate and continue to the finals.

Final round
Winterthur win 3–1 on aggregate and are promoted to Nationalliga B.

 Bellinzona win 14–0 on aggregate and are promoted to Nationalliga B.

First round
Montreux-Sports continue to the final.

Küsnacht] continue to the final.

Final round
'' Küsnacht win 6–1 on aggregate. Montreux-Sports are relegated to 2. Liga.''