The American National Standards Institute is a non-profit organisation that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organisation also coordinates U.S. standards with international standards so that American products can be used worldwide.

ANSI is also the Microsoft collective name for all Windows code pages. Sometimes used specifically for code page 1252, which is a superset of ISO/IEC 8859-1.