TPN may refer to:
Science and Medicine Total parenteral nutrition Triphosphopyridine nucleotide, the previous name for nicotinamide adenine dinucleotide phosphate (NADP+) Task Positive Network, see Dorsal attention network
Organisations Society of Friends of Science in Warsaw () in Warsaw Tatra National Park, Poland ()
Other Third-party note or Note verbale, a diplomatic document Tupinambá language, by ISO 639 code Tiputini Airport, Ecuador Treaty on the Prohibition of Nuclear Weapons The Promised Neverland (manga/anime series)