International Association of Classification Societies_IACS
- Country: United Kingdom
- Type: Organization
- Website: www.iacs.org.uk
- Update: 05-02
International Association of Classification Societies (International Association of Classification Societies; abbreviated as IACS) is an international professional organization founded in 1968, with a total of 12 members including American Bureau of Shipping, China Classification Society, Det Norske Veritas, Lloyd's Register.