| Agency Name: | National Security Authority |
| Nativename: | Národní bezpečnostní úřad |
| Picture Caption: | Main building |
| Formed: | 1998 |
| Headquarters: | Prague, Czech Republic |
| Chief1 Name: | Jiří Lang |
| Chief1 Position: | Director |
National Security Authority (Czech: Národní bezpečnostní úřad, NBÚ) is a Czech government agency responsible for maintaining security clearances, protection of classified information and cyber security of the Czech Republic. NBÚ is also charged with protection of the Czech government communications and information systems against penetration and network warfare.