Isa may refer to:

• Isa Miranda, Italian actress
• Isa (album), a 2004 album by Enslaved.
• Isa (dance), a local variation of a Jota.
• Isa (moth), a moth genus.
• Isa (name), a common Arabic name. Also a shortened form of the Montenegrin name Isailo.
• Isa, a prophet in the Quran who is generally taken as an expression for Jesus in Islam.

Places

• Isa, Nigeria, a local government area in Sokoto State
• Mount Isa, Queensland, a city in northwest Queensland, Australia.
• Isa, Kagoshima, a planned city in Japan
• Isa District, Kagoshima, a district in Japan scheduled to dissolve when the City of Isa opens

ISA is a three-letter acronym that may stand for:

In Engineering

• Instrument Society of America, now called the Instrumentation, Systems, and Automation Society, is a non-profit technical society for engineers, technicians, businessmen, educators and students, who work, study or are interested in industrial automation and pursuits related to it.

In chemistry

• Isosaccharinic acid, a product of degradation of cellulose at high pH, strongly complexing some actinides in radioactive waste conditioned in cement.

In politics:

• International Seabed Authority, an intergovernmental body based in Kingston, Jamaica established to organize and control all mineral-related activities in international seabed areas.
• International Searching Authority, a patent office performing prior art searches during the prosecution of international (patent) applications under the Patent Cooperation Treaty.
• Internal Security Act, laws that enable the executive government of a jurisdiction to preserve the internal security of the nation.
• Ideological State Apparatus, a term used by Marxist philosopher Louis Althusser for how society reshapes the individual in its own image.

In computing:

• Industry Standard Architecture, a now-obsolete I/O bus standard for IBM-compatible PC motherboards.
• Instruction Set Architecture, the complete specification of the interface between computer programs that have been written and the underlying computer hardware that carries out the actual work.
• Information Security Architecture, a buzzword variant for information security.
• ISA platform ("NOS"), an operating system software for Nokia mobile telephones.
• Microsoft Internet Security and Acceleration Server, a Microsoft server product.
• Instrumentation, Systems, and Automation Society, formerly the Instrument Society of America, a professional organization for instrument engineers.
• Isa (computer science), a relationship between objects; for instance, an apple tree "is a" tree.

In aviation and space exploration:

• International Standard Atmosphere, a tabulation with altitude of the standard variation of pressure, temperature, density, viscosity, etc., appropriate to mid latitudes, released by the ICAO.
• Iranian Space Agency, Iran's governmental space agency.
• Israeli Space Agency, Israel's governmental space agency.
• Italian Space Agency, Italy's governmental space agency.

In education:

• Independent Schools Association (Australia), a grouping of schools primarily based in Sydney, Australia, for the purposes of sporting competitions.
• Independent Schools Association (UK), one of the oldest of the independent schools’ organisations in the UK. The association is a constituent association of the Independent Schools Council
• Institute for the Study of the Americas, a research institute associated with the University of London's School of Advanced Study
• International School of the Americas, a magnet school located in San Antonio, Texas.
• International School Amsterdam, an international school in the Netherlands.
• International School of Arizona, a not-for-profit school located in Scottsdale, Arizona.
• International School of Aleppo, the only international school in Syria and it's located in Aleppo city
• International Studies Association, an association of political science and international relations scholars
• Investigative Skills Assessment, part of some GCSE Science Syllabii
• Instituto Superior de Arte an art school in Havana, Cuba
• Intensive Support Amount a component of education funding in Ontario 1998-2005, worth $12,000 (level 2) or $27,000 (Level 3) per year, per claimed pupil supposedly to fund one-on-one support; claims doubled to about C$1 billion between 2002 and 2004.

In finance:

• International Standards on Auditing, professional standards for the performance of audits of financial information.
• Individual Savings Account, a financial account for investment in the UK with special tax rules.
• Israel Securities Authority, the Israeli regulator of financial and stock market.

ISA can also refer to:

• Intelligent speed adaptation
• Information System Audit
• Intelligence Support Activity, a special operations unit of the U.S. Army.
• Infectious salmon anemia, a viral disease of salmon.
• Institut de Sélection Animale, a poultry breeding company based in Saint–Brieuc, France.
• International Security Alliance, a fictional spy agency on the NBC soap opera Days of our Lives.
• International Shakespeare Association, an international academic association based in Stratford-upon-Avon, UK.
• International Sign Association, a trade-organization of sign producers.
• International Society of Arboriculture, a non-profit botanical organization.
• International Sociological Association, a non-profit organization in the fields of sociology and the social sciences.
• International Standard Atmosphere, a definition of pressure, temperature, humidity and so forth, under the SI convention.
• Interplanetary Strategic Alliance, an alliance in the video game Killzone and its sequels.
• International Symbol of Access, an image of a stylized person in a wheelchair against a blue background, meant to designate handicap accessibility at a glance.
• Interstellar Alliance, an alliance in Babylon 5 to fight the Shadows.
• Irish Sailing Association, the governing body for sailing in Ireland.
• Independent safety assessment, a type of safety audit.
• Independent Safeguarding Authority, a body created in England, Wales and Northern Ireland to help prevent unsuitable people from working with children and vulnerable adults.
• Grupo ISA, a Colombian utility.