A battlestar group is by basic definition a formation of Colonial military vessels consisting of a battlestar and its accompanying support ships. These support ships may fulfil offensive and defensive combat roles (dedicated heavy gun ships, smaller carriers), as well as combat support roles (logistics, medical, repair facilities).

The concept of a battlestar group can also encompass several battlestar formations operating as a combined, coordinated combat package — permanently assigned, or assembled as a task force for a specific mission — under one commander, typically an admiral. This is a possibility given the number of available battlestars at the outbreak of hostilities with the Cylons.