The title of supreme fleet commander designated the individual in overall command of the New Republic Defense Fleet throughout the New Republic Era. In the days of the Rebel Alliance Navy, this position was referred to as supreme commander of the Alliance fleet, chief commander of the naval forces of the Alliance, or commander of the Rebel Alliance fleet.
Admiral Raddus, a Mon Calamari, established the groundwork for the Rebel Alliance Navy and acted as its primary commanding officer. After Raddus's death during the Battle of Scarif, Gial Ackbar, also a Mon Calamari and his ally, succeeded him. Ackbar took control of the expanding Alliance Military, thereby assuming leadership of the Rebel navy and becoming the supreme commander of the Alliance fleet.
In his capacity as supreme commander, Ackbar led rebel forces in the Battle of Endor. He remained the supreme commander throughout the subsequent conflicts of the early New Republic Era. He possessed this title during the Battle of Jakku, which marked the concluding battle of the Galactic Civil War.