It is found off Japan, China and the Koreas as well as western and southern Australia and the coastlines of New Zealand in the western Pacific and from the Gulf of Alaska to the Gulf of California and from Ecuador to Chile in the eastern Pacific. The basking shark is typically seen swimming slowly at the surface, mouth agape in open water near shore. This species also travels further offshore as well and is know to enter bays and estuaries. Basking sharks are often seen traveling in pairs and in larger schools of up to a 100 or more. Its common name comes from its habit of 'sunning' itself at the surface, back awash with its first dorsal fin fully exposed.
Basking sharks are highly migratory.
Off the southwest coast of the United Kingdom in the northeast Atlantic, the basking shark feeds at the surface of coastal waters during the summer. These sharks are absent from November to March, suggesting a migration beyond the continental shelf during the winter months. Sightings of groups of individuals of the same size and sex suggest that there is pronounced sexual and population segregation in migrating basking sharks. The basking shark is one of the most recognizable of all sharks. Its massiveness, extended gill slits that nearly encircle the head and lunate caudal fin together help distinguish it from all other species.