Chondrichthyans (sharks, rays, and chimaeras) are among the most threatened vertebrates, with 37% of species threatened (Critically Endangered, Endangered, or Vulnerable) on the International Union for Conservation of Nature (IUCN) Red List of Threatened Species. Immediate conservation action is essential to halt population declines and support species recovery. The Important Shark and Ray Areas (ISRA) initiative, led by the IUCN Species Survival Commission Shark Specialist Group, was launched in 2022 with the aim to identify and delineate critical habitats for chondrichthyans globally. ISRAs are defined as ‘discrete, three-dimensional portions of habitat, important for one or more shark, ray, or chimaera species, that have the potential to be managed for conservation’. The ISRA framework is grounded in four science-based criteria and seven sub-criteria, addressing species vulnerability, range restriction, life-history processes (reproduction, feeding, resting, movement, undefined aggregations), and special attributes (distinctiveness, diversity). The ISRA Criteria are applicable across all aquatic environments—marine, estuarine, and freshwater. ISRAs are identified through an expert-led process planned over a series of 13 regional workshops covering global waters. Eight global regions have been assessed: Central and South American Pacific, Mediterranean and Black Seas, Western Indian Ocean, Asia, Polar Waters, New Zealand and Pacific Islands, South American Atlantic, and South American Inland Waters. These regions cover over 70% of the world’s marine and freshwater systems. To date, 694 ISRAs have been delineated for 409 species, informed by the contributions of 1, 039 experts across. Reproductive Areas were the most commonly life-history processes identified, primarily in coastal zones. The final five regions—European Atlantic, Australia and Southeast Indian Ocean, North America and Caribbean Atlantic, African Atlantic, and North American Pacific—are scheduled for completion by 2027. ISRA findings offer a science-based foundation for integrating chondrichthyan habitats into marine spatial planning and protected area design. They support evidence-informed decision-making to advance global biodiversity conservation goals.