The International Virtual Observatory Alliance or IVOA is a worldwide scientific organisation formed in June 2002. Its mission is to facilitate international coordination and collaboration necessary for enabling global and integrated access to data gathered by astronomical observatories. An information system allowing such an access is called a Virtual Observatory. The main task of the organisation so far has focused on defining standards to ensure interoperability of the different virtual observatory projects already existing or in development.

The IVOA now comprises 19 VO projects from Argentina, Armenia, Australia, Brazil, Canada, China,Europe, France, Germany, Hungary, India, Italy, Japan, Korea, Russia, Spain, Ukraine, theUnited Kingdom, and the United States. Membership is open to other national andinternational projects according to the IVOA Guidelines for Participation.

Senior representatives from each national VObs project form the IVOA ExecutiveCommittee. A chair is chosen from among the representatives and serves a 1.5year term, preceded by a 1.5 year term as deputy chair. The ExecutiveCommittee meets 3-4 times a year to discuss goals, priorities, and strategies.