Keigo Hagiya is a Japanese actor and voice actor born on November 7, 1996, in Saitama Prefecture, Japan. His entertainment career began in 2007 when he joined the Johnny & Associates talent agency. During his time with the agency, he appeared in several television dramas, including roles in "BAD BOYS J" (2013) and "SHARK 2nd Season" (2014). He left Johnny & Associates in November 2018 and is now a member of the entertainment group 7ORDER.

Hagiya made his debut as an anime voice actor in 2022, taking on the role of Light in the television series Technoroid Overmind. This series is part of a larger media mix franchise that combines anime, games, and music, with a story set in a futuristic Tokyo where androids compete in singing and dancing performances. Light is a member of the top-tier group STAND-ALONE within the series. In a comment about his role, Hagiya expressed his happiness at being part of the project and his intention to promote the anime with enthusiasm, mirroring his character's role as the one in charge of fan service and social media. The anime was produced by Doga Kobo and premiered in July 2022.

In addition to his role in Technoroid Overmind, Hagiya has contributed to voice work for music projects. In 2025, he participated in the Sanrio character song cover album "My Bestie Voice Collection II," performing the song "Happy Sentai★Hapidanbui". This album featured various popular voice cast members each collaborating with a Sanrio character. Beyond his voice acting career, Hagiya has an extensive portfolio of work in live-action television, film, and stage productions, including a leading role in the 2020 stage adaptation of "Poupelle of Chimney Town".