剧情设置在现代巴黎，中法混血的Marinette Dupain-Cheng（玛丽内特杜平-程）是一个普通的中学女生，性格有些犹疑羞涩，梦想成为时装设计师，暗恋同班的帅气男生Adrien Agreste（阿德里安阿格里斯特）。当有坏人威胁巴黎时，Marinette化身正义勇敢的英雄Ladybug（瓢虫），搭档爱调戏人的Chat Noir（黑猫），一起打击邪恶势力。但Marinette并不知道面具下的Chat Noir正是她一直不敢表白的男生Adrien，而Adrien也不知道自己的暗恋对象Ladybug却是Marinette。Set in modern-day Paris, the series focuses on a teenage junior high school girl named Marinette Dupain-Cheng and her classmate and crush Adrien Agreste. When evil arises, Marinette becomes a superhero named Ladybug, while Adrien becomes Chat Noir/Cat Noir. Not knowing each other's true identity, the two work together to protect Paris from a villain named Hawk Moth who covets their powers.