NNT could refer to:
- Nan Airport, Thailand; IATA airport code NNT.
- The Nakai–Nam Theun National Biodiversity Conservation Area (NBCA), located in Laos
- Nassim Nicholas Taleb
- Number needed to treat, an epidemiological measure
- Nunthorpe railway station, England; National Rail station code NNT.
- National News Bureau of Thailand by The Government Relations Department (Thailand)
- NAD(P) transhydrogenase, a human mitochondrial enzyme encoded by the NNT gene.