A now-defunct organization dedicated mainly to the development of the data processing language Cobol and associated software. It originated at a meeting, the Conference on Data Systems Languages, called in the Pentagon by the US Department of Defense in 1959 to consider both the desirability and feasibility of establishing a common language for data processing. The acronym for that conference, CODASYL, became the name of the continuing organization. The initial version of the language, COBOL-60, was published the following year, with subsequent versions being adopted by ISO.

During 1965–67 CODASYL established a Database Task Group (DBTG) to investigate and develop proposals for a common database management system to be used in association with Cobol as the host language (see database language). In 1969 a report giving a specification was published and widely discussed. A revised report published in 1971 allowed also for other languages to be used as the host programming language. IDMS is the leading product based on these proposals.

CODASYL itself no longer exists, although some of its committees continue to operate. See CODASYL network model.