The 1999–2000 Regionalliga was the sixth season of the Regionalliga as the third tier of German football. It was also the last season to be competed in four divisions. Teams were not only competing for promotion to the 2. Bundesliga, but also to qualify for the new two-division Regionalliga. As in the previous seasons there were four divisions: Nord, Nordost, West/Südwest and Süd. Each division comprised 18 teams, with the exception of the West/Südwest division that had 20. Nord VfL Osnabrück was promoted to 2nd Bundesliga by beating 1. FC Union Berlin in the play-offs. VfB Lübeck, Eintracht Braunschweig, SV Wilhelmshaven, SV Werder Bremen Amateure and Lüneburger SK qualified for the new two-division Regionalliga. Final table The remaining teams were relegated to the Oberliga. Top scorers Nordost 1. FC Union Berlin remains in the Regionalliga, as the club could not secure promotion in the play-off against VfL Osnabrück. 1. FC Union Berlin took part in the play-offs against LR Ahlen and SC Pfullendorf, but could not win promotion. Dresdner SC, FC Erzgebirge Aue, FC Carl Zeiss Jena, SV Babelsberg 03, FC Sachsen Leipzig and Rot-Weiß Erfurt qualified for the new two-division Regionalliga. Final table The remaining teams were relegated to the Oberliga. Top scorers West/Südwest 1. FC Saarbrücken was promoted to the 2nd Bundesliga. LR Ahlen won promotion to the 2nd Bundesliga by beating 1. FC Union Berlin and SC Pfullendorf in the play-offs. Teams ranked from 3 to 11 qualified for the new two-division Regionalliga. The remaining teams were relegated to the Oberliga. Final table Top scorers Süd SSV Reutlingen 05 was promoted to the 2. Bundesliga. SC Pfullendorf took part in the play-offs against 1. FC Union Berlin and LR Ahlen, but could not win promotion. Teams ranked 3 to 13 qualified for the new two-division Regionalliga. Teams ranked below 13 were relegated to the Oberliga. FC Augsburg and Karlsruher SC Amateure were forcibly relegated. Top scorers Promotion playoffs Round 1 The champions of the Regionalliga Nord (VfL Osnabrück) and Regionalliga Nordost (1. FC Union Berlin) faced each other in a two-legged playoff. Osnabrück, as winners, were promoted to the 2. Bundesliga, while Union were given another chance at promotion in round 2. Round 2 1. FC Union Berlin faced the runners up of the Regionalliga West/Südwest (LR Ahlen) and Regionalliga Süd (SC Pfullendorf) in a round-robin tournament. Ahlen won this mini-league, and took the final promotion place.