The Czech Republic National Basketball League (NBL) (Czech: Národní Basketbalová Liga) is the top-tier level professional basketball league in the Czech Republic. It is run by the Asociace Ligových Klubů. The league operates under a promotion and relegation system. The bottom two NBL teams from each season's standings are relegated to the 2nd-tier level 1. Liga, while the top two 1. Liga teams from each season's standings are promoted to the NBL.

ČEZ Nymburk has won every league title since the 2003–04 season.