Ken Uo is a Japanese voice actor, narrator, and actor from Saitama Prefecture, born on July 13, 1965. His real name is Makoto Sasaki. He is currently affiliated with the talent management firm Kenyu Office, having moved there at the end of 2014 after previously working with Yu-Rin Pro.

Before entering the voice acting industry, Uo worked as a photographer. His interest in voice acting was sparked while observing audio recording sessions during his photography work on film sets. He pursued this new path later in life, beginning his professional voice acting career at the age of 33 after training at the Yokozawa Keiko Voice Actor & Narrator School. He also gained stage experience as a member of the theatrical group Urban Forest, which was active until 2010.

Since his debut in the 1990s, Uo has built a prolific career characterized by versatility, voicing a wide range of characters across anime, video games, and dubbed foreign productions. His vocal range, described as a natural tenor to baritone, allows him to portray characters of various ages and temperaments, from heroes and villains to comedic roles and elderly figures. He is also active as a stage actor and narrator for documentaries, radio programs, and commercials.

Uo has accumulated an extensive list of anime credits. He is known for roles such as the Galactic King and Karin in Dragon Ball Super, Amayo Jingoro in Basilisk, and the recurring role of the Grandfather in the Fruits Basket reboot series. Other notable anime roles include Sofu, the late grandfather of Hapu, in Pokémon Sun & Moon, Gungabee Inuta in Hakkenden: Eight Dogs of the East, and characters in long-running franchises like Detective Conan and One Piece. In the 2000s, he had roles in series such as The Familiar of Zero, where he voiced Marteau, and Soul Eator, where he played Sonson-J. More recent roles include Kintarō Kataoka in Bullbuster and Mitsuhiro Ide in Ultraman. He also plays the roles of Newman in Banished From The Heroes' Party, Gerard Bogard in Isekai Cheat Magician, Katsuhito Masaki in Tenchi Muyo! Ryo Ohki, Katsuya's Father in Fruits Basket -prelude-, and Taisho Sushiya in Beyblade X.

Beyond anime, Uo is highly active in video game voice work, often providing additional voices for major international titles localized for the Japanese market. His game credits include contributions to critically acclaimed series such as Final Fantasy VII Rebirth, Dragon Quest XI, God of War, Horizon Forbidden West, and Detroit: Become Human. He is also the official voice of the Disney character Horace Horsecollar for appearances at Tokyo Disneyland. In the realm of foreign language dubbing, he is a frequent Japanese voice for actors Eddie Marsan, Simon Yam, and Toby Jones. His dubbing work also includes the role of Cyborg in the Japanese version of the Teen Titans animated series.

Ken Uo is regarded by colleagues for his professionalism, friendly demeanor, and the reliability he brings to his craft. His late start and subsequent long-standing career serve as a notable example of dedication to the profession. Outside of work, his hobbies include futsal, mountain climbing, and photography.