Rei Hiroe is a Japanese manga artist and original character designer, born on December 5, 1972. He is best known as the creator of the long-running manga series Black Lagoon, which has been adapted into multiple anime productions, and as the original concept creator for the original anime series Re:CREATORS.

Hiroe's early career in the manga industry began in the 1990s, with his first works serialized by Kadokawa Shoten. These early projects, including titles such as Hisuikyo Kitan and Shook Up!, were ultimately unsuccessful and cancelled. During this period, he also worked on dōjinshi under the pseudonyms Read Bear or Red Bear and TEX-MEX. Seeking a new direction, he moved to the publisher Shogakukan in the early 2000s, where he was eventually given the opportunity to create a new action series.

Hiroe's professional breakthrough came with Black Lagoon, a manga he has written and illustrated since its debut in Shogakukan's seinen magazine Monthly Sunday Gene-X in April 2002. The series follows a crew of mercenaries operating a torpedo boat in the seas of Southeast Asia. Hiroe has stated that he was inspired to create the series by news reports of piracy in the South China Sea, which he felt perfectly suited his desire to craft a dynamic and original story about modern outlaws who know no borders. Among his creative influences, he counts novelist James Ellroy as his favorite, as well as Stephen King for atmosphere, and manga artists such as Mikiya Mochizuki, Akihiro Ito, and Kenichi Sonoda. He has also cited the Franco-Belgian comic series Soda and the Spanish comic Blacksad as graphic influences.

The popularity of Black Lagoon led to its adaptation into an anime television series. The first season, also titled Black Lagoon, aired in 2006, and was followed by Black Lagoon: The Second Barrage in the same year. These were later supplemented by Black Lagoon Omake, a series of short comedic episodes, and Black Lagoon: Roberta's Blood Trail, a five-episode original video animation series that concluded in 2011. For these productions, Hiroe was credited as the original creator, with his manga serving as the source material.

After a period of sporadic chapter releases for Black Lagoon, Hiroe returned with a major new project as an original creator for the 2017 anime series Re:CREATORS. For this series, he provided the original story concept and original character designs. The narrative of Re:CREATORS focuses on fictional characters from various anime, games, and literature who manifest in the real world to confront their creators. Hiroe has drawn a deliberate comparison between the series and the 1993 film Last Action Hero. Following the debut of Re:CREATORS, Hiroe resumed regular publication of new chapters for Black Lagoon.

Beyond his work on manga series, Hiroe has contributed to other projects as an artist. He served as the character designer for the Elf character in the anime Bikini Warriors and was a manga character designer for Fate/Grand Order: The Grand Temple of Time. A collection of his illustrations, titled Barrage: Rei Hiroe Artworks, was released in 2007, and includes the previously uncollected four chapters of his early work Phantom Bullet. His artistic style is characterized as gritty, dynamic, and highly detailed, particularly in its rendering of weaponry and military hardware.