Ladybug retains many of her alter ego's characteristics, but she is much stronger and her confidence, cleverness, and bravery are more prominent. Her quick-thinking, resourcefulness, and wit are more obvious, especially when she is figuring out how to utilize her Lucky Charm. As Ladybug, she strives to rescue everyone, including those akumatized by Hawk Moth. No matter the difficulty of her tasks, she does everything in her power to set things right while keeping up with her life.

Cat Noir says whatever comes to his mind and makes plenty of typically cat-related jokes and puns. In his attempts to get Ladybug's attention, along with other people, he brags and boasts about himself in a comedic way. Much of Cat Noir's exaggerated personality, especially his flirting with Ladybug, stems from entertainment such as anime, television, and movies due to his lack of experience with people his age. His change to his superhero status doesn't diminish his kindness.

Tikki is a kwami that is connected to the Ladybug Miraculous, which Marinette Dupain-Cheng currently owns. With the help of Tikki's power, Marinette uses her earrings to transform into Ladybug.

Plagg is a kwami that is connected to the Cat Miraculous, which Adrien Agreste currently owns. With the help of Plagg's power, Adrien uses the ring to transform into Cat Noir.

Marinette Dupain-Cheng is one of the main protagonists of Miraculous: Tales of Ladybug & Cat Noir. Marinette is a student in Miss Bustier's class at Collège Françoise Dupont in Paris, France. She is also a budding fashion designer. With the Ladybug Miraculous, when inhabited by Tikki, Marinette transforms into the superhero Ladybug, gaining the power of good luck and creation.

Adrien Agreste is one of the main protagonists of Miraculous: Tales of Ladybug & Cat Noir. He is a student in Miss Bustier's class at Collège Françoise Dupont in Paris, France. He is also a fashion model for his father's brand. With the Cat Miraculous, when it is inhabited by Plagg, Adrien transforms into into the superhero Cat Noir ("Chat Noir" in the French version), gaining the power of bad luck and destruction.

Alya Césaire is Marinette's best friend and a student in Miss Bustier's class at Collège Françoise Dupont. She is also the sole admin of the Ladyblog and head of the school blog. In "Lady Wifi", after Alya gets suspended from school because of Chloé, she is infected with an akuma by Hawk Moth and becomes Lady Wifi, a supervillain whose powers come from her smartphone and its wifi signal.

Nino Lahiffe is Adrien's best friend and a student in Miss Bustier's class at Collège Françoise Dupont. In "The Bubbler", when Nino can't get Gabriel Agreste to allow Adrien have a birthday part and is considered a bad influence, Hawk Moth infects him with an akuma to transform him into the Bubbler, a bubble-wielding supervillain.

Chloé Bourgeois is Marinette's rival and a student in Miss Bustier's class at Collège Françoise Dupont. Her father, André Bourgeois, is the mayor of Paris. In "Antibug", after Ladybug ignores her suggestions on how to beat Vanisher and calls her a liar, she is infected with an akuma by Hawk Moth and becomes Antibug, an anti-Ladybug supervillain.