Hidenari Ugaki is a Japanese actor and voice actor born on July 25, 1963, in Tokyo, Japan. He is affiliated with the talent agency 81 Produce. A graduate of the Toho Gakuen School of Music, he entered the Bungakuza Theatre Institute in 1984, where he was a classmate of fellow voice actor Takaya Kuroda. He began his career appearing in television dramas before shifting his focus to voice acting, which includes work in anime, video games, dubbing, and narration.

Ugaki is known for his deep, robust, and often macho voice, which he frequently uses to portray middle-aged to elderly characters. Despite this powerful on-screen persona, his natural speaking voice is described as soft and gentle. This versatility has allowed him to take on a wide range of roles, from heroic figures to comedic characters and even villains. He is also active in narrating commercials and providing audio commentary for various media.

He has an extensive filmography across numerous popular anime series. He is recognized for roles such as Argo Gulskii in Mobile Fighter G Gundam, Kannari-san in the 2005 Doraemon series, and Yama in One Piece. He has also appeared in long-running franchises, providing voices for characters in Naruto (as Fūjin), Boruto: Naruto Next Generations (as Gatai), Gintama, and JoJo's Bizarre Adventure: Stardust Crusaders (as Khan and Chaka's father). In addition to these, his portfolio includes the roles mentioned by the user, such as Professor in The Human Crazy University, Shibata Katsuie in Kochoki, Ussu in Gon, and Danjo Tozawa in Dead Mount Death Play. He has also voiced Kuma Father across multiple Sylvanian Families series, Harumichi Bouya in Kōkō Butō Den Crows, Red Hakaider in Kikaider-01, Grenadier in Cosmo Warrior Zero, and Death Tyranno in Dinozaurs.

In the realm of video games, Ugaki is highly acclaimed for his portrayal of Goro Majima in the Yakuza (Like a Dragon) series. This role became a landmark in his career and a fan favorite, with his unique, self-styled interpretation of the Kansai dialect, dubbed "Majima dialect" by the scriptwriter, contributing significantly to the character's popularity. His other notable game roles include Ganryu in the Tekken series, Birdie in Street Fighter V, and Wen Kinoc and O'aka XXIII in Final Fantasy X.

Ugaki has also been a regular voice actor in the Super Sentai tokusatsu series, frequently voicing monsters and villainous characters. His first regular role in the franchise was as the Apostle of Infinity, Voffa, in Bakuryu Sentai Abaranger. His dubbing work is extensive, covering live-action films and Western animation. He is known for providing the Japanese voice of Donatello in the TV Tokyo edition of the Teenage Mutant Ninja Turtles anime and its related films. He also dubbed roles such as Slade in Teen Titans and Stanford Pines in Gravity Falls.

Standing 182 cm tall, his hobbies and special skills include skiing and swimming. He has been married, though he keeps his personal life private.