A fleet is a large grouping of Starships traveling together or assigned to particular duty.

The term fleet can be applied to any significant gathering of starships as well as to refer to the totality of a power's space based forces. Military powers with large numbers of vessels often organize their forces into specific fleets commonly referred to by a numerical designation.

Starfleet operated numerous numerical fleets made up of hundreds of starships. These fleets were usually commanded by a high ranking Flag officer, such as an Admiral or Fleet Admiral.