OAS

OAS or Oas may refer to:

Chemistry

Open-Architecture-System, the main user interface of Wersi musical keyboards
OpenAPI Specification (originally Swagger Specification), specification for machine-readable interface files for RESTful Web services
Oracle Application Server, software platform

Open aortic surgery, surgical technique
Oral allergy syndrome, food-related allergic reaction in the mouth
2'-5'-oligoadenylate synthase, an enzyme
- OAS1, OAS2, OAS3, anti-viral enzymes in humans

Office of Aviation Services, agency of the United States Department of the Interior
Ontario Archaeological Society, organization promoting archaeology within the Province of Ontario, Canada
Organisation Armée Secrète, French dissident terrorist organisation, active during the Algerian War (1954–62), fighting against Algerian independence
Organization of American States, continental organization of the Western Hemisphere
Oxford Art Society, society for artists in the city of Oxford, England

Ohio Auction School, school for auctioneers in Ohio, U.S.
Old Age Security, social security payment available to most Canadians aged 65 or older
Option-adjusted spread, the yield-curve spread of a fixed-income security, adjusted for the cost of embedded options
Oas, Albay, municipality in the Philippines