NNC can stand for:
- Naga National Council, a predecessor of the Nationalist Socialist Council of Nagaland (NSCN)
- Natal Native Contingent, British auxiliary soldiers in South Africa around late 19th century
- National Nanotechnology Competition, of Iran
- National Nutrition Council (Philippines)
- National Negro Congress, Black liberation organisation in the United States
- National Nuclear Center, of the Republic of Kazakhstan
- National Nuclear Corporation (later officially just NNC), a company formed by the merger of companies that built the UK's nuclear power stations; bought by AMEC in 2005
- National Numismatic Collection, a part of the National Museum of American History
- neonatal care
- neonatal cholestasis
- neonatal conjunctivitis
- neonatal cutting
- Nepal Nursing Council
- Nobel Night Cap, the student festivity at the end of the Nobel Prize week
- North Northamptonshire Council, England
- Northwest Nazarene College, now called Northwest Nazarene University, Idaho, United States
- Norwegian Nobel Committee