Keitarō Takahashi is a Japanese manga artist best known as the creator of Jormungand, an action series about an international arms dealer that was adapted into the anime Jormungand and its second season, Jormungand Perfect Order. Born in Kanagawa Prefecture on September 15, though the year of his birth is not widely publicized, Takahashi made his professional debut as a mangaka in 2002 with the work Ordinary in Kodansha's Monthly Afternoon Season Zokan. Prior to his mainstream debut, he created dōjinshi under the name Tokyo Ponpondo and briefly attended the Department of Graphic Design at Tama Art University.

Takahashi began his most famous work, Jormungand, in Shogakukan's Monthly Sunday GX magazine in 2006. The manga, which follows the young arms dealer Koko Hekmatyar and her team of bodyguards, ran until 2012 and was compiled into thirteen volumes. The series was later adapted into a two-season anime television production by the studio White Fox. The first season aired in 2012 covering the first half of the manga, followed by the second season, Jormungand Perfect Order, later that same year to complete the story.

Following the conclusion of Jormungand, Takahashi launched the series Destro 246 in Monthly Sunday GX in 2012. The manga, which focuses on a female assassin known as Number 246, completed its run in 2016 and was collected into six volumes. He later began the series The Poor, The Holy Ark, and the Rich in 2017, which has been on hiatus since November 2020. A prequel to Destro 246 titled Destro 016 began serialization in 2021. In addition to his original serialized manga, Takahashi illustrated the novel Tonari no Dopple-san published under Shueisha's SD Bunko imprint.

Takahashi's artistic identity is strongly tied to action-oriented narratives featuring capable female protagonists and detailed depictions of military hardware, firearms, and combat. His personal interests, including photography, collecting toy guns and military goods, as well as his stated admiration for films such as Heat, Miami Vice, and The Usual Suspects, inform the cinematic and tactical quality of his work. Within the manga industry, Takahashi is recognized for his long-running association with Monthly Sunday GX, where the majority of his major works have been serialized, and for creating a successful property that received a complete anime adaptation.