N9 may refer to:

• N9 road (Belgium), a road connecting Brussels and Ostend, passing Aalst, Ghent, Eeklo and Bruges (see nl:N9 (België))
• N9 road (France)
• N9 road (Ireland)
• N9 road (Netherlands), a road connecting Alkmaar and De Kooy
• N9 road (South Africa), a road connecting George and Colesberg
• N9 road (Switzerland)
• Nebraska Highway 9, a state highway in the U.S. state of Nebraska

• Fairey N.9, a British seaplane
• Jero N° 9 Antwerpen 1911, a 1911 aeroplane
• London Buses route N9
• N9, a postcode district in the N postcode area
• N9, the Nokia N9 model N9-00, a MeeGo Linux phone
• Negeri Sembilan, one of the 13 states in Malaysia
• Netscape Navigator 9, a web browser created by Netscape Communications
• Nonoxynol-9, a molecule
• North Coast Aviation IATA airline designator
• Northrop N-9, company designation of the Northrop YB-35 flying wing bomber
• Northrop N-9M, research aircraft, built as a flying mockup of the Northrop YB-35
• LNER Class N9, a class of British steam locomotives

• N°9, a shortening for Number nine

• 9N (disambiguation)