PPO may refer to:
Law enforcement Personal protection officer Personal protection order Police protection order Prisons and Probation Ombudsman Public prosecutor's office
Chemistry and biochemistry 2,5-Diphenyloxazole, an organic scintillator Polyphenol oxidases, a family of enzymes Poly(p-phenylene oxide), a type of plastic Propylene oxide, an industrial chemical Protoporphyrinogen oxidase, an enzyme Pure plant oil
Other uses White House Presidential Personnel Office, the White House office tasked with vetting new appointees Preferred Provider Organization, a type of health insurance Pfadfinder und Pfadfinderinnen Österreichs, an Austrian Scouting organization Planned purchase order, part of the purchasing process Polish Patent Office Political Parties Order, 2002, a chief executive order in Pakistan Toray Pan Pacific Open, a Women's Tennis Association tournament Philippine Philharmonic Orchestra Abbreviation of Praefectus Praetorio (Praetorian Prefect), found on inscriptions Proximal Policy Optimization, a family of reinforcement learning algorithms (part of computer science) Populist Party Ontario, a minor provincial political party in Ontario, Canada Plant Phenology Ontology