Rogue Leader, or Rogue One, was a title and callsign given to the commander of the elite Rebel Alliance/New Republic/Galactic Alliancestarfighter group, Rogue Squadron. Because of Rogue Squadron's fame, the person holding the title of Rogue Leader was often considered the best active pilot in the Defense Force. Since only one Rogue Leader was ever killed in action—Lensi—and he was shot down by a previous Rogue Leader—Wedge Antilles—this is understandable. Various pilots have taken that position over the years.
During the Battle of Gall in 3 ABY, Antilles used the callsign Rogue One, although he had been serving as Rogue Leader. The callsign was given temporarily to Luke Skywalker during the battle.