Marinette Dupain-Cheng (French pronunciation: [maʁinɛt dypɛ̃ tʃɛŋ]) is a fictional character and the female protagonist of the animated television series Miraculous: Tales of Ladybug & Cat Noir created by Thomas Astruc. Depicted as a teenage student of Chinese, French, and Italian descent, she aspires to become a fashion designer and lives with her parents, Tom Dupain and Sabine Cheng, who own a bakery. After she passes the test of Master Fu, the keeper of the magical objects named the Miraculouses, by helping him, Marinette is chosen as a soon-to-be superheroine alongside Cat Noir (French: Chat Noir, lit. 'Black Cat'). As a result, she is given a pair of earrings known as the Ladybug Miraculous, which when worn grants Marinette the ability to transform into Ladybug, her superheroine alias. Ladybug and Cat Noir's goal is to protect Paris from the villain Hawk Moth (French: Papillon, lit. 'Butterfly') and defeat him altogether. Unknown to Marinette, Cat Noir's civilian identity is Adrien Agreste, a classmate whom she has feelings for. As the holder of a Miraculous, Marinette is assisted by a small red creature resembling a ladybug called Tikki, who is a magical being known as a kwami. As Ladybug, Marinette's signature ability is creation (through her Lucky Charm superpower). Marinette appears in most Miraculous media, including the main series, the film, the Roblox game, the mobile running game, and the comic books.

Marinette's character was inspired by a young woman wearing a ladybug-themed T-shirt who once worked with Astruc. After creating a drawing that portrayed her as a ladybug-themed superheroine, Astruc felt this would be a good character, especially as he was not aware of the existence of another ladybug-related superhero. The woman's haircut served as inspiration for Marinette's hairstyle as well. Marinette is voiced by Cristina Vee in the English dub, while Anouck Hautbois voices her in the French version of the series.

Marinette's character has received a generally positive critical response, with writers characterizing her as a role model for viewers and as a great protagonist; both her civilian self and her superheroine identity have been praised. Meet-and-greet sessions with Ladybug have taken place. Several pieces of merchandise based on her, such as accessories, clothing items, and action figures, have been created.