DNO may refer to:

• The Danish Nurses' Organization, a trade union for nurses in Denmark
• Director of Naval Ordnance, British Admiralty administration
• Distribution Network Operator, companies licensed to distribute electricity in Great Britain
• Dno (air base), a former air base in Russia located 4 km south of Dno
• DNO ASA, a Norwegian oil company
• Drang nach Osten, a term coined in the 19th century to designate German expansion into Slavic lands
• Dutch National Opera, based in Amsterdam, The Netherlands

Dno is a town and the administrative center of Dnovsky District in Pskov Oblast, Russia, located at the intersection of the Pskov–Bologoye and St. Petersburg–Kiev railways, east of Pskov, the administrative center of the oblast. Population:

Founded as a railway center in 1897, it was granted town status in 1925. The territory used to be a part of Porkhovsky Uyezd of Pskov Governorate, and Dno was the seat of Dnovskaya Volost.