# Osa

Osa or OSA may refer to:

## Places

* Osa Peninsula, in Costa Rica
* Osa (canton), in the province of Puntarenas in Costa Rica
* Osa Conservation Area, an administrative area in Costa Rica
* Osa, India, a village in Allahabad, India
* Osa, Iran, a village in Mazandaran Province, Iran
* Osa, Warmian-Masurian Voivodeship, north Poland
* Osa, Norway, a village in Ulvik municipality, Vestland county, Norway
* Osa, Russia, the name of several inhabited localities in Russia
* Osa, Missouri, a community in the United States
* Old Scona Academic High School, a school in Edmonton, Canada
* Oakland School for the Arts

## Military

* Osa-class missile boat
* 9K33 Osa (SA-8 Gecko), a Soviet surface-to-air missile launcher
* M79 Osa, a Serbian/Yugoslav rocket launcher
* Avia B.122 Osa, a Czech trainer aircraft
* Osa (handgun) a Russian non-lethal handgun

## Science and technology

* Optical spectrum analyzer
* Osa (plant), a monotypic genus of plant in the family Rubiaceae

### Medicine

* Obstructive sleep apnea, a sleep-related breathing disorder wherein episodes of upper airway obstruction lead to reduced breathing that interrupts normal sleep
* Osteosarcoma, a malignant neoplasm of bone

### Computing

* Open Scripting Architecture, for AppleScript
* Open Services Access, a set of standards for mobile telecommunications
* Online Sexual Activity
* Open Systems Adapter, an IBM card for mainframes
* Open systems architecture, a telecommunication standard

## Businesses and organizations

* Oceania Swimming Association
* Ontario Soccer Association
* Ontario Society of Artists
* Open Solutions Alliance
* Optical Society of America, now Optica
* Optimization Systems Associates, a defunct American software company
* Order of Saint Anna, a Russian order of chivalry
* Order of Saint Augustine (Ordo Sancti Augustini), the Roman Catholic Augustinian order
* Oregon Student Association
* Organization of the Secret Army, French far-right nationalist group in Algeria
* OSA, a Czech Republic performance rights organisation
* Oriental Society of Australia, now the Australian Society for Asian Humanities
* OSA Group, a Constructivist architectural association of the 1920s based in the USSR
* The Odisha Society of the Americas
* Intelligence-Security Agency of Bosnia and Herzegovina (Obavještajno sigurnosna / bezbjednosna agencija, or OSA-OBA), an intelligence and security agency of Bosnia and Herzegovina
* Office of the Science Advisor, of the United States Environmental Protection Agency
* Office of Special Affairs, a controversial department of the Church of Scientology
* Operation Save America

## People

* Sumire Haruno, Japanese actress, nicknamed Osa
* Osa Maliki (1907–1969), Indonesian politician
* Osa Massen (1914–2006), Danish actress
* Osa Odighizuwa (born 1998), American football player
* Lars Osa (1860–1958), Norwegian artist

## Other uses

* Old Stone Age or Paleolithic
* Office of Secret Actions, a fictional government department in the video game Return to Castle Wolfenstein
* Official Secrets Act, legislation in several countries
* Online Safety Act 2023, United Kingdom legislation
* Online savings account
* Open skies agreement
* Osaka International Airport (former IATA code: OSA)