The Vice Chief of Naval Operations (VCNO) is the second highest ranking officer in the United States Navy. In the event that the Chief of Naval Operations (CNO) is absent or is unable to perform his duties, the VCNO assumes the duties and responsibilities of the CNO. The VCNO may also perform other duties that the CNO assigns to him. The VCNO is appointed by the President of the United States, and must be confirmed via majority vote by the Senate. By statute, the VCNO is appointed as a four-star admiral.
This position was called Assistant for Operations in 1915, and Assistant Chief of Naval Operations in 1922. In 1942 the title became Vice Chief of Naval Operations. The current VCNO is Admiral Jonathan W. Greenert.