Circumglobal in coastal warm temperate and tropical seas. Western Atlantic: New Jersey, USA to Uruguay, including the Gulf of Mexico and Caribbean. Eastern Atlantic: western Mediterranean to Namibia. Indo-Pacific: Red Sea, East Africa and throughout the Indian Ocean; Japan to New Caledonia, Hawaii and Tahiti. Eastern Pacific: southern California, USA to Ecuador, probably Peru.

A large hammerhead with a notch at the center of head; 1st dorsal fin moderately high, 2nd dorsal and pelvic fins low. Front margin of head broadly arched with prominent median notch. Side wings of head narrow, rear margins swept backward. Uniform grey, grayish brown, or olivaceous above, shading to white below; pectoral fins tipped with grey or black ventrally.

A coastal-pelagic, semi-oceanic shark occurring over continental and insular shelves and adjacent deep water, often approaching close inshore and entering enclosed bays and estuaries.