ASTM International, known until 2001 as the American Society for Testing and Materials (ASTM), is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. The organization's headquarters is in West Conshohocken, Pennsylvania, about 5 miles (8 km) northwest of Philadelphia.

ASTM, founded in 1898 as the American Section of the International Association for Testing and Materials, predates other standards organizations such as BSI (1901), DIN (1917), ANSI (1918) and AFNOR (1926). ASTM has a dominant role among standards developers in the USA, and claims to be the world's largest developer of standards. Using a consensus process, ASTM supports thousands of volunteer technical committees, which draw their members from around the world and collectively develop and maintain more than 12,000 standards.

ASTM International publishes the Annual Book of ASTM Standards each year in print, Compact Disc (CD) and online versions. The online version was available by subscription and cost was based upon usage. For 2008, the complete set of books or CDs cost almost US$9000 and included 81 volumes. For 2010, the complete set of books or CDs cost almost $9700 and included 82 volumes.