N15 may refer to:

Roads

• N15 road (Belgium), a National Road in Belgium
• Route nationale 15, in France
• N15 road (Ireland)
• A15 motorway (Netherlands)
• Nebraska Highway 15, in the United States

Vehicles

• HMS Triton (N15), a submarine of the Royal Navy
• LNER Class N15, a British 0-6-2 steam locomotive class
• LSWR N15 class, a British 4-6-0 steam locomotive
• Nissan Almera (N15), a Japanese automobile sold in Europe
• Nissan Pulsar (N15), a Japanese automobile sold domestically

Other uses

• N15 (Long Island bus), New York
• Enterobacteria phage N15
• Kingston Airport (Nevada), in Lander County, Nevada, United States
• London Buses route N15
• Nitrogen-15, an isotope of nitrogen
• Tonga language (Malawi)
• N15, a postcode district in the N postcode area