ISO character set (disambiguation) ISO image, a file containing the whole contents of an optical disc ISO base media file format, a container format for time-based multimedia files ISO 5800, a film speed system Digital camera ISO, light sensitivity of a digital image sensor ISO 8601, a date format ISO(n), the Euclidean group Infrared Space Observatory, a space telescope active from 1995 to 1998 International Science Olympiad, a series of science competitions for students Iso (fish), a genus of surf sardines in the family Notocheiridae Isomer, chemicals with the same chemical formula but different structures Isorhapontigenin, a stilbenoid (chemical) Isotonitazene, a benzimidazole-derived opioid analgesic drug, colloquially referred to as "iso" ISO: integumentary sensory organ