IPO, or initial public offering, a type of securities offering in which a private company goes public.

IPO or ipo may also refer to:

• Immersion pulmonary oedema, a malady of swimmers and divers
• Intellectual Property Office (disambiguation), a government agency in many nations
• Intellectual Property Organisation of Pakistan
• Intellectual Property Owners Association
• International Philosophy Olympiad
• International Progress Organization, a Vienna-based think tank dealing with world affairs
• Interdecadal Pacific oscillation, an oceanographic/meteorological phenomenon
• Internationale Prüfungsordnung (IPO), an international dog sport, also known as Schutzhund
• Instituto Português de Oncologia, in Portugal
• IPO station, a metro station at the University of Porto, Portugal
• Israel Philharmonic Orchestra
• IPO model (input-process-output), a conceptual model of computer systems
• Interprocedural optimization, a computer program optimization method
• Independent Party of Oregon
• International Police Organization
• Ipiko language, an ISO 639-3 code