IPN may refer to:

• Instant payment notification

• Interpenetrating polymer network, form of chemical copolymer
• Isopropyl nitrate, a liquid monopropellant

• IPN, a type of I-beam used on European standards

• Interplanetary Internet
• InterPlaNet
• InterPlanetary Network, a group of spacecraft equipped with gamma-ray burst detectors

• Infectious pancreatic necrosis, disease in fish
• Interpeduncular nucleus, a region of the brain

• Independent Practitioners Network association for practitioners in psychotherapy, counselling, and related fields
• Index of Place Names in Great Britain
• World Bank's Inspection Panel of the World Bank Group
• Instytut Pamięci Narodowej (Institute of National Remembrance), a Polish historical research institute
• Instituto Pedro Nunes, technology transfer center of the University of Coimbra
• Instituto Politécnico Nacional (National Polytechnic Institute), Mexican university
• International Policy Network (1971–2011), former British think tank
• International Polio Network, former name of Post-Polio Health International
• IPN, IATA code for Usiminas Airport in Minas Gerais, Brazil
• International pitch notation, a method to specify musical pitch