NPO may refer to:
Medicine , Latin for 'nothing by mouth', a medical instruction to withhold oral intake of food and fluids neurogenic pulmonary oedema
Science North Pacific Oscillation, a teleconnection pattern in atmospheric conditions over the North Pacific NP optimization problem, an optimization problem that is NP-hard NPO, characterizing thermal stability of a capacitor The NPO complexity class, standing for "NP-optimization problem", in computational complexity
Organisations Nonprofit organization National Portfolio Organisation, a UK-based culture and arts organisation receiving substantial funding from Arts Council England National Ports Organisation, former part of the UK Department for Transport National Preservation Office, part of the British Library Scientific Production Association (, ), a form of scientific research-to-production facility in the Soviet Union and the Russian Federation. ('Netherlands Public Broadcasting'), governing body of the Netherlands (Dutch) Public Broadcasting System ('Dutch public broadcasting system'), the public broadcasting service in the Netherlands Netherlands Pathfinder Organisation (), one of the organisations that evolved into Scouting Nederland, the national Scouting organisation NPO UK Ltd., a chain of stationery and book shops in Northern Ireland, now part of Eason & Son National Printing Office, one of the three recognized government printers of the Philippines National Parents Organization, non-profit charitable and educational organization in the United States that promotes shared parenting.
Other Nanga Pinoh Airport, Indonesia (IATA code) Pochuri language, of Nagaland, India (ISO 639 code)