Kōsuke Kobayashi is a Japanese voice actor born on January 28, 1980, in Toyama Prefecture, Japan. He is affiliated with the agency Raccoon Dog, having previously been with Pro-Fit. He is a graduate of the Pro-Fit Voice Actor Training School and speaks the Toyama dialect.

Kobayashi has built a career through a wide range of supporting and guest roles across numerous anime series, films, and video games. His voice acting work spans from the mid-2000s to the present, with a significant volume of credits in the 2020s. He is known for providing voices for various characters, often including townsfolk, monsters, soldiers, and other supporting figures in major anime productions.

Among his more specific credited roles, Kobayashi played the character Nozo in the series Sex Salon and the role of Luó Jiā in Thunderbolt Fantasy Sword Seekers 4. His other notable anime roles include Conrad in Spy x Family. He has also appeared in numerous other popular series in a variety of parts. His credits include roles such as a Count in Frieren: Beyond Journey's End, a Japanese Language Teacher in My Dress-Up Darling, a Coach in the film Haikyu!! The Dumpster Battle, and multiple monster and character voices in The Reincarnation of the Strongest Exorcist in Another World. He has voiced multiple characters in Yashahime: Princess Half-Demon, including a Sea Dragon, a Raccoon Dog Gatekeeper, and various demons and villagers. Additional appearances include roles in Rurouni Kenshin, The Saint's Magic Power Is Omnipotent, Tengoku Daimakyo, Remake Our Life!, Sword Art Online, Tada Never Falls in Love, March Comes In Like a Lion, the classic series Another, and Air. His work also extends to the series Star Wars: Visions, where he voiced a Stormtrooper.

Kobayashi has also contributed to video games. While a complete list of his game roles is not specified in available records, his professional credits include work in the video game industry.