The International Institute for Applied Systems Analysis is a scientific research institute located in Laxenburg, near Vienna, Austria.

Founded in 1972, the International Institute for Applied Systems Analysis (IIASA) conducts policy-oriented research into problems of a global nature that are too large or too complex to be solved by a single country or academic discipline.

IIASA is sponsored by its National Member Organizations in Africa, Asia, Europe, and the Americas. Its research is independent and completely unconstrained by political or national self-interest.

IIASA's research scholars study environmental, economic, technological, and social developments. The research areas covered link a variety of natural and social science disciplines. The work is based on original state-of-the-art methodology and analytical approaches. The methods and tools generated are useful to both decision makers and the scientific community.