Blue Leader, also designated as Blue One, functioned as the callsign for the commanding officer of Blue Squadron.
In the course of the Clone Wars, Jedi Commander Ahsoka Tano utilized this specific callsign in both the Battle of Ryloth and the Battle of Mon Cala.
Throughout the Galactic Civil War, General Antoc Merrick operated as Blue Leader during the battle of Scarif, where he met his death.
Subsequently, a certain pilot operating under this particular callsign was eliminated by Darth Vader during the battle that took place at Vrogas Vas.
In the Battle of Jakku, the commander of 77 Squadron (which participated as Blue Squadron in that engagement) employed this callsign.
During the Battle of Starkiller Base, Captain Temmin Wexley, a Resistance pilot, flew as Blue One.
During the evacuation of D'Qar, Tallissan Lintra fulfilled the role of Blue Leader.
During the Mission to Batuu, a male individual identified as Blue Leader established contact with Resistance personnel on the planet to verify the acquisition and transit of the desired Datacard to General Organa. He then expressed gratitude to Vi Moradi for her contributions.