PNN may refer to: National Natural Parks System (Colombia) (; PNN; "Parques Nacionales Naturales"), the Colombian governmental agency responsible for the country's national park system Parliamentary and News Network, Australia Princeton Municipal Airport (Maine), USA (by IATA code) Probabilistic neural network, a machine learning algorithm Pinin (PNN protein) the protein encoded by the PNN gene Hagahai language (ISO 639 code: pnn) VOA-PNN (Persian News Network) Voice of America Planetary nebula nucleus (PNN), see planetary nebula Perineuronal net, a component of the extracellular matrix See also Pinin (disambiguation)