The New Republic Second Fleet functioned as a significant fleet element within the New Republic Defense Fleet. Established in 4 ABY following the Battle of Endor, the Second Fleet was among the New Republic Navy's original four fleets and participated in the New Republic liberation campaign until the capture of Coruscant.
The Second Fleet's base of operations was the New Republic stronghold located in the Calamari sector. Despite an initially successful campaign in 4 ABY, the Second Fleet experienced a substantial setback due to an Imperial raid targeting the Hast Shipyards, resulting in the destruction of numerous vessels and a subsequent pause in operations within the northern regions of the galaxy.
Beginning in 8 ABY, the Second Fleet transitioned into a primary defensive command for the New Republic, stationed at Elom situated in the Borderland Regions. During the Thrawn campaign, it acted as a rapid response fleet.
Just before the onset of the Yevethan Great Purge in 16 ABY, after a lengthy period of patrolling Thunder Alley, the Second Fleet was reassigned to Coruscant for home guard duties.
During the Yuuzhan Vong War, the Second Fleet was deployed near Ralltiir in the time leading up to the Battle of Fondor. It was later reorganized as the Galactic Alliance Second Fleet.