Masaomi Yamahashi is a Japanese voice actor born on July 8 in Oita Prefecture, Japan. He began his career in the voice acting industry during the 2010s. As of April 2025, he is affiliated with the agency EARLY WING, following the closure of his previous agency, Office PAC, on March 31, 2025.

Yamahashi has built a career with a wide variety of roles in anime, video games, and dubbed foreign productions. One of his prominent anime roles is as James Mirror, known as Jim, in the 2023 Netflix original anime series Make My Day. He is also well known for voicing the character Grimlock in the Japanese version of the Transformers Adventure anime. His other anime credits include roles in series such as Heavenly Delusion, Zom 100: Bucket List of the Dead, Blade of the Immortal, and an appearance in the Star Wars: Visions short Tatooine Rhapsody. He has also been credited in numerous other shows, including The Legendary Hero Is Dead!, Tengoku Daimakyo, and Cyberpunk: Edgerunners, often in supporting or guest roles.

Beyond anime, Yamahashi is an active voice actor in the video game industry, with credits in major titles such as Final Fantasy VII Remake and its sequel Final Fantasy VII Rebirth, Kingdom Hearts III, and Monster Hunter Stories 2. He is also a prolific voice actor for dubbing foreign films and television series, providing the Japanese-language voice for characters in Hollywood productions like Mad Max: Fury Road, the 2019 version of The Lion King, and various projects within the Marvel Cinematic Universe and Star Wars franchise, including series like Loki, Hawkeye, and The Mandalorian.