# Sis

Sis or SIS may refer to:

## People

* Michael Sis (born 1960), American Catholic bishop

## Places

* Sis (ancient city), historical town in modern-day Turkey, served as the capital of the Armenian Kingdom of Cilicia.
* Kozan, Adana, the current name of the Armenian town of Sis in Cilicia, Turkey
* Sis, Armenia, a village in Armenia
* Sis, Azerbaijan, a village in the Republic of Azerbaijan
* Sis, Iran, a city in East Azerbaijan, Iran
* Sis, Kurdistan, a village in Kurdistan, Iran
* Sis Rural District (Shabestar County), East Azerbaijan province, Iran
* Sis Rural District (Dehgolan County), Kurdistan province, Iran
* Mountains of Sis, a range of the Pre-Pyrenees

## Intelligence

* Schengen Information System, in Europe
* Security Information Service, Czech domestic information intelligence agency known as BIS
* Secret Intelligence Service, UK intelligence agency, also known as MI6
* Australian Secret Intelligence Service, Australia’s national intelligence service
* Canadian Security Intelligence Service, Canada's national intelligence service
* New Zealand Security Intelligence Service, an intelligence agency of the New Zealand government
* Finnish Security Intelligence Service, the intelligence agency of Finland in charge of national security
* Slovenská informačná služba, Slovak Intelligence Service
* Special Intelligence Service, a secret FBI intelligence agency operating in South America during World War II
* Signals Intelligence Service, the former United States Army codebreaking division
* Information and Security Service of the Republic of Moldova, the principal intelligence agency of Moldova.
* Serviço de Informações de Segurança, a Portuguese intelligence agency
* Survey of India Service, formerly the Great Trigonometric Survey
* Special Investigation Section, a tactical detective and surveillance unit of the Los Angeles Police Department
* Signals Intelligence Section, involved with the Magic project during World War II

## Businesses

* Silicon Integrated Systems, an electronics manufacturing company
* Sports Information Services, a news service company
* Siemens IT Solutions and Services, a service provider which is part of Siemens AG headquarters
* SIS (motorbikes), a Portuguese manufacturer of motorcycles

## Schools
### China

* Shekou International School, in Shekou
* Singapore International School, in Hong Kong
* South Island School, in Hong Kong

### United States

* School of International Service, American University, Washington, D.C.
* Syracuse University School of Information Studies
* University of Pittsburgh School of Information Sciences

### Other schools

* SIS Swiss International School, a group of 15 private day schools in Switzerland, Germany and Brazil
* McGill University School of Information Studies, Canada
* School of International Studies of the Dresden University of Technology, Germany
* Singapore International School Mumbai, India
* Surabaya International School, Indonesia
* Seoul International School, South Korea
* Stockholm International School, Sweden
* Sharjah Indian School, United Arab Emirates

## Other organizations

* Sisters in Islam, an organization based in Malaysia
* Swedish Institute for Standards
* Specialized Information Services, a division of the United States National Library of Medicine
* State Information Service, official media and public relations apparatus of the Egyptian state

## Information processing

* SIS (file format), Symbian OS filename extension
* Short integer solution problem, a problem in lattice-based cryptography
* Single-instance storage, information-storage space-saving mechanism
* Strategic information system, a part of corporate strategy
* Student information system, a software application for education establishments to manage student data
* Sequential Importance Sampling

## Biological sciences

* Small intestinal submucosa, transplantation tissue
* Second-impact syndrome, synergy in concussions
* Sex in space, an area of biological research

## Healthcare

* Saline infusion sonography, a test used to diagnose uterine polyps
* Shoulder impingement syndrome, tendinitis of the shoulder

## Technologies

* Selective inverted sink, frost protection device
* Safety instrumented system or safety instrumentation system
* Space Infrastructure Servicing, a robotic spacecraft for in-space refueling of communication satellites
* Sequential infiltration synthesis, a method to infiltrate polymers to create inorganic-organic hybrid materials

## Other uses

* SIS (group), South Korean girl group founded 2017
* SiS (TV series), a morning talk show
* SIS, a 2008 television film directed by John Herzfeld
* Supervised injection site
* MS Sis, car ferry
* Singular isothermal sphere profile, a simple density distribution used in astronomy
* Silicon monosulfide, chemical formula SiS
* SIS (Soft Is Strong), 2024 EP by Katseye