Main characters ; : :A 16-year-old Galactic Alliance ensign. Trained as a soldier since birth, Ledo finds himself shipwrecked on Earth following a failed attempt by the army to destroy the Hideauze's home planet. As he interacts with his new surroundings and gets used to the crew of the
Gargantia, Ledo is exposed to some concepts of human society long forgotten by his civilization (or at least obscured from its soldiery) due to its permanent state of total war against the Hideauze, like entertainment, cooperation and tolerance. Ledo gradually grows attached to his new friends on
Gargantia. ; : :Chamber is Ledo's masculine
mecha and
artificial intelligence assistant; a mass produced robot used in great numbers by the Galactic Alliance of Humankind. Chamber describes itself as a program designed specifically to ensure that its pilot excels at his or her assigned task, which in the case of Ledo is a soldier. Upon meeting the people of the
Gargantia, Chamber manages to analyze and decode their language to act as a translator between Ledo and the people on
Gargantia. ; : :A 15-year-old messenger who meets Ledo when he wakes up from hibernation and serves as his guide. She becomes Ledo's first and best friend, and from all the members of
Gargantia, she is the one who gets closest to him, usually keeping him company and encouraging his efforts to fit himself into the fleet's environment. She eventually falls in love with him. ; : :A Galactic Alliance feminine robot designed for higher ranked soldiers originally used by Ledo's superior officer, Kugel. Off-screen, they also crash-land on Earth and join a fleet, but assume totalitarian militaristic control over it. After Kugel dies from illness, Striker assumes his identity and continues to command the fleet, serving as the series antagonist in later episodes. ; : :A 22-year-old high rank officer at the
Gargantia, she is Fleet Commander Fairlock's second in command and daughter of his predecessor, Chevron. Following Fairlock's death, she takes over as Fleet Commander, following his wish. ; : :The 18-year-old leader of the
Gargantias excavation team. ; : :The head of the
Gargantias repairmen. His older brother was killed by whalesquid, and upon learning of Ledo's intention to exterminate them due to their connection to the Hideauze, he decides to assist him with the pretense of exploring the whalesquid territory for salvage work. After Ledo clears the area of the whalesquid, Pinion claims the technology salvaged by his crew to establish his own fleet, which is later annexed to Kugel's fleet. In the occasion, Pinion is appointed to be chief technician of Kugel's fleet in charge of developing weapons for it.
Supporting characters ; : :Kugel was the commander of all Machine Caliber pilots aboard the GAH carrier Lamorak. As a commander he was privy to the knowledge that the Hideauze were humans who modified themselves to be able to live in outer space. Kugel piloted the machine caliber Striker X3752. 5 carriers were seen at the Closer pass but only one Striker Machine Caliber was seen during the battle, so the depths or extent of Kugel's authority is not fully known. He eventually dies and Striker takes command in his death. ; : :Amy's 10-year-old little brother with an illness that compromises his health, thus he is usually bedridden, and only moves by a wheelchair. He befriends Ledo, who treats him as a younger brother. ; : :The fleet commander of the
Gargantia, who despite being sick, refuses to relinquish his post. He appoints Ridget as his successor just before he passes away. ; : :Amy's friend and a reserved 15-year-old messenger. ; : :A hyper 14-year-old messenger who is also Amy's friend. She leaves
Gargantia along with the many who decide to follow Pinion's plan. ; : :Amy's pet flying squirrel. ; : :The resident doctor aboard
Gargantia who is seen as the "sage" and runs a library atop a tower. ; : :A pirate leader who launched an attack on the
Gargantia after Ledo kills some of her men to protect Bellows and her crew. Some time after being defeated by the
Gargantias forces with Ledo's help, she reappears as part of Kugel's fleet, yet she helps to rebel against it. ; : :A major shipleader in the
Gargantia who agrees with Pinion's plan and secedes from the fleet to accompany his efforts to reclaim technology from ancient civilizations. Later he is forced to join Kugel's fleet along the rest of his crew.
Other characters ; : :A new character from the OVA series, she is a former member of Kugel's fleet who moves to the
Gargantia and becomes the newest member of Amy's messenger team. She is later revealed as a spy for an unknown party, ordering a machine which resembles Chamber. ; : :One of the ship commanders on the Gargantia. ; : :A young repair girl aboard
Gargantia. She joins Pinion when he leads a group of the fleet away. ; : :A mysterious lady. ; : :Ridget's childhood friend. She is gentle-hearted, but she is brisk and efficient when it comes to her nursing job. Seven years before, Storia left the
Gargantia to live with Ritona. ; : :An old acquaintance of Ridget, he was chief mechanic of another fleet who went derelict after its main engine was damaged beyond repair. Before that, he falls in love with Storia and takes her to live with him. ==Production==