Yoku Shioya is a Japanese voice actor, actor, and sound director born on June 24, 1958, in Kagoshima Prefecture, though he grew up in Kawasaki City from the age of five. His real name is Tsubasa Shioya. He is the younger brother of fellow voice actor Kōzō Shioya.

Shioya began his entertainment career as a child actor at the age of eight after joining the Himawari Theatre Group. He made his voice acting debut at fourteen, providing the voice for the titular character in the 1972 anime Umi no Triton. At the time, he was the youngest member of the Japan Actors' Association to debut in voice acting. A significant early role was as Jinpei the Swallow (G-4) in the long-running Science Ninja Team Gatchaman series, including Gatchaman II and Gatchaman Fighter. He voiced this character from the age of fourteen, with his voice changing during the show's production.

Throughout the 1970s and 1980s, Shioya became a prolific voice actor, taking on a wide range of leading and supporting roles in anime. He voiced Cosmo Yuki in the Space Runaway Ideon series and its compilation films, The Ideon: A Contact and The Ideon: Be Invoked. He played Akira Kiso in the series and movie God Mars. In the 1980s, he also took on numerous roles in the Transformers franchise, including Buster in Transformers: Super God Masterforce, Hellbat in Transformers: Victory, and various characters in Transformers: Scramble City such as Bumble and Fireflight. Other notable roles from this era include Yuzuru Shiga in The Laughing Target, the title character in Kariage-kun, Triton in the Umi no Triton film, Jabao Jaba in Magical Taruruuto-kun, Phillip in Kyōfu Densetsu: Kaiki! Frankenstein, and Private 1st Class Abe in The Harp of Burma.

In the 1990s, he continued to secure memorable parts, most famously as Ryota Miyagi in the enduringly popular basketball anime Slam Dunk. He also voiced Sorrento of Siren in Saint Seiya and its subsequent Hades Chapter OVA, Bōichi Nekota in Odin: Starlight Mutiny, and Takao Shibuya in the acclaimed film Perfect Blue.

Around the year 2000, Shioya expanded his focus in the industry to include sound direction. While his voice acting work became less frequent, he took on the role of sound director for numerous anime series, including Basilisk: The Kouga Ninja Scrolls, Welcome to the N.H.K., and White Album. He has also worked as a lecturer at voice acting training schools.

Despite his shift in focus, Shioya has continued to take on notable voice roles in the 2010s and beyond. He voiced Will A. Zeppeli in the 2012 adaptation of JoJo's Bizarre Adventure, Noir in Kirakira PreCure a la Mode, and has appeared in series such as By the Grace of the Gods and Blue Miburo. His contributions to voice acting were recognized in 2017 when he ranked 19th in TV Asahi's "Voice Actor General Election". In addition to his anime work, Shioya has an extensive career in dubbing foreign films and television shows, providing the Japanese voice for characters like Donatello in the live-action Teenage Mutant Ninja Turtles films and Artie Ziff in The Simpsons.