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