The 1999–2000 Slovak First Football League (known as the Mars superliga for sponsorship reasons) was the seventh season of first-tier football league in Slovakia, since its establishment in 1993.

ŠK Slovan Bratislava were the defending champions.

A total of 16 teams was contested in the league, including 14 sides from the 1998–99 season and two promoted from the 2.

FC Rimavská Sobota and BSC JAS Bardejov was relegated to the 1999–2000 2.

The two relegated teams were replaced by FK DAC 1904 Dunajská Streda and FK VTJ Koba Senec.