Masahiro Kobayashi is a Japanese actor and voice actor born on May 16, 1971, in Yakumo, Hokkaido. He began his career in 1995 when he enrolled in the Seinenza Theater Company and later became affiliated with the Gekidan Seinenza theater group. Kobayashi has maintained an active career spanning from the mid-1990s to the present, working extensively in television dramas, films, and voice acting for anime and video games.

Kobayashi is best known for his voice role as Barret Wallace in the Final Fantasy VII compilation series. He first voiced the character in the 2005 CGI film Final Fantasy VII: Advent Children, a role he would reprise in the video game Dirge of Cerberus: Final Fantasy VII in 2006. When director Tetsuya Nomura was selecting a voice actor for the film, he initially considered Kobayashi for the role of the character Loz before ultimately casting him as Barret. Kobayashi has described his approach to the character as treating Barret as unrefined but also dependable and unique, always trying to keep his upbeat character and good outlook in mind. He worked to give Barret a booming, confident-sounding voice, though at times the director instructed him to take it up a notch. He later voiced the character again in the 2020 remake Final Fantasy VII Remake. For the later title Final Fantasy VII Rebirth, the role was taken over by Mahito Funaki, as Kobayashi had retired from voice acting.

Beyond his work in Final Fantasy, Kobayashi has voiced several other notable characters in anime and games. In the boxing anime Hajime no Ippo, he voiced Jason Ozuma in 2000. He provided the Japanese dub voice for Jerome Chef McElroy in the animated series South Park from 2001 to 2006. In the 2015 animated film The Boy and the Beast, he had a voice role. Within the video game medium, he played Ryid Uruk in Final Fantasy Type-0 and its high-definition version in 2011 and 2015, and he voiced Bahamut in World of Final Fantasy in 2016. He also had a voice role as a warrior in the Japanese dub of Jak and Daxter: The Precursor Legacy in 2001.

Kobayashi has maintained a significant career in live-action Japanese television and film alongside his voice work. His television drama credits include roles in GTO as Hajime Hakamada, White Tower as Shinichi Yasunishi, and the popular series 1 Litre of Tears as Shintaro Tanabe. He also appeared in the tokusatsu series Kamen Rider Kabuto as Negishi. In film, he appeared in the 2001 kaiju movie Godzilla, Mothra, King Ghidorah: Giant Monsters All-Out Attack as Teruaki Takeda. The majority of his career, however, has been built on supporting and guest roles in numerous Japanese television dramas, including series such as Saint's March, Aoi Jidai, and the long-running detective drama Aibou.