'Jocko' was the informal designation of a US naval attack against the Japanese positions on Iwo Jima island (23/24 June 1944).

On 23 June Rear Admiral Joseph J. Clark’s Task Group 58.1 departed the island of Saipan in the Mariana islands group to attack Iwo Jima, and on the following day re-formed and headed to Eniwetok atoll.