ISS generally refers to the International Space Station, but may also refer to:

Imperial Star Ship, in the Star Trek Mirror Universe is a space ship of the Terran Empire

Imaging Science Subsystem, a set of cameras aboard the Cassini spacecraft

Input to state stability, which is a notion in control theory

Ion scattering spectroscopy, a materials analysis method.

International Superstar Soccer, series of Japanese soccer video games by Konami

Innisdale Secondary School, a high school in Barrie, Ontario

Idea Star Singer, A Malayalam music reality show by Asianet TV.

Instruction Set Simulator, computer program that simulates a processor at the instruction-set level

Institute for Security Studies regional think tank in Africa

Indian Springs School, a boarding school in Birmingham, Alabama

Internet Security Systems, security software vendor

Institute for Security Studies (EU) a European Union think tank

Institute of Social Studies, international institute of higher education on social and economic change with a focus on development processes

ISS A/S, a Danish service company

Injury Severity Score, an established medical score used to asses the severity of trauma

International Social Services, a charitable, non-governmental organisation

Industrial Sounding System, proposed method of launching inert objects into low orbit with the use of a cannon

Institute of Strategic Studies regional think tank in Pakistan

International School of Stavanger, a private Primary, Middle and High School in Stavanger, Norway