PSO

PSO may refer to:

In music:
 * Pacific Symphony Orchestra
 * Peoria Symphony Orchestra
 * Pittsburgh Symphony Orchestra
 * Plano Symphony Orchestra
 * Portland Symphony Orchestra
 * Perth Symphony Orchestra

In science and technology:
 * Particle swarm optimization, a swarm intelligence optimization technique
 * Password Settings Object, used in Windows Active Directory environments
 * Phase-shift oscillator, an electronic circuit that generates sine waves
 * Protocol Support Organization, one of the three initial components of ICANN, later disbanded
 * PSO J318.5-22, a rogue planet discovered in 2013

Other uses:
 * Pakistan State Oil
 * Patient safety organization
 * Paysite operator, the operator of a paysite, typically pornographic
 * Peace Support Operations, a military term used by NATO
 * Penalty shootout, a method of determining a winner in sports matches which would have otherwise been drawn or tied
 * Phantasy Star Online, a series of online role-playing video games
 * Phantasy Star Online, the first game in the series
 * Phone sex operator, a person who provides phone sex service
 * Producers Sales Organization, an independent motion picture production and distribution company
 * Protective services officer, a member of police in Australia who performs policing duties at specific locations
 * Psoriasis, an autoimmune disease
 * PSO-1, a Soviet telescopic sight
 * Public Safety Officer, another name for police, firefighters, ambulance crews and other providing safety services in the U.S.
 * Public Service Company of Oklahoma
 * Public service obligation, a form of state subsidy for transport links which are not commercially viable
 * Puro Sangue Orientale, a breed of horse in Italy
 * The FAA LID code for Stevens Field airport in Archuleta County, Colorado, United States.
 * The IATA code for Antonio Nariño Airport, serving the Colombian city of Pasto
 * It also refers to Personal Security Officers.
 * Provider Services Operations, a team at the National Marrow Donor Program