Admiral (大将, taishō) is a title of admiral signified senior command rank in the Marines. Admirals, also known generally as flag officers, were typically responsible for a high level military command at battle group or fleet level, and/or for administrative and political duties relating to Marine operations.

In One Piece, Admirals are shown as being the second highest rank behind the Fleet Admiral.
Marine Admirals
The three Marine Admirals, three hours before Ace's execution.

In the One Piece world, there are only three Marines with the title of Admiral. They are known by their aliases: "Aokiji" (Blue Pheasant), "Akainu" (Red Dog), and "Kizaru" (Yellow Monkey). The Admirals and Fleet Admiral Sengoku are the only Marines within the World Government who have the authority and ability to issue a Buster Call.

The Admirals are crowned the World Government's "Ultimate Attack Force", and are the strongest individual fighters within the World Government and the Marines.

Fleet Admiral Sengoku was once an Admiral prior to his promotion; this was during the Ohara Incident.

Should a World Noble be opposed or injured, an Admiral will be summoned to take down the assailants who did the damage. Failure is not acceptable.

List of Admirals

* Aokiji (Real name: Kuzan; Promoted from Vice Admiral rank)
* Akainu (Real name: Sakazuki; Promoted from Vice Admiral rank)
* Kizaru (Real name: Borsalino)
* Sengoku (Promoted to Fleet Admiral rank)