Chief Petty Officer

Chief petty officer (CPO) is an enlisted naval rate, a type of military rank used by the service organizations of different cultures. As a traditional naval grade, CPO is senior to a petty officer. In comparison to infantry ranking systems, this rank is approximately equivalent to the more senior sergeant grades. Personnel of this grade can be addressed simply as chief, and sometimes by their job title, such as "chief specialist."

While chiefs are subordinate to all commissioned officers, they have far more experience and practical knowledge than ensigns and lieutenants, and are expected to act as mentors to them and to the junior enlisted assigned. As such, chiefs are often among the actual leaders in a Star Fleet organization. Chiefs serve with distinction in most Star Fleet branches and specialties, but are particularly visible in engineering and other technical trades.

There are usually individual grades of chief petty officers, differentiated by first, second class, etc; more senior CPOs are referred to as senior chief petty officer (SCPO) or master chief petty officer (MCPO), referred to as "senior chief" or "master chief" (respectively) in conversation.

The origins of the rank Chief Petty Officer can be traced to Earth, where the title was used in the United States Navy.

When Sergey Rozhenko spied Miles O'Brien as the transporter chief aboard the USS Enterprise, NCC-1701-D in 2367, Rozhenko was excited to meet another chief petty officer. When O'Brien introduced himself, he acknowledged Rozhenko as 'sir', to which Rozhenko told him not to call him 'sir', because he used to work for a living. Sergey's wife, Helena, then told O'Brien that he was just joking and that Sergey's proudest moment was when their son, Worf, had earned his commission. Sergey then added, "Imagine. An old enlisted man like me raising a boy to be an officer!"

Several years later, O'Brien was identified by a Jem'Hadar as the rank of "Chief Petty Officer," or "what Star Fleet refers to as a 'noncom'," adding "you must have a great deal of experience...that makes you a priority target."

In 2374, Cadet Dorian Collins of the USS Valiant, NCC-74210, introduced herself to Nog and Jake Sisko (External Link) as "Acting Chief Petty Officer."

Trainees	Enlisted Personnel			Non-Commissioned Officers
Rct	CMR	CMA	CM	PO3	PO2	PO1	CPO	SCPO	MCPO	CMCPO	MCPOSF
Trainees	Commissioned Officers							Flag Officers
Cdt	Mid	Ens	Lt[JG]	Lt	LCdr	Cdr	Capt FCapt	Cmdr	RAdm	VAdm	Adm	FAdm