Kazuya Kobayashi is a Japanese voice actor from Tokyo, previously affiliated with the agency 81 Produce. He is known for providing voices in numerous anime series, primarily in supporting and background roles, throughout the 2000s.

Kobayashi is perhaps best recognized for his role as Naga in the anime series Monster Rancher, which aired from 1999 to 2001. Naga is one of the main villains in the series, serving as the cruel second-in-command to the primary antagonist, Moo.

His extensive anime credits include a variety of minor roles across many popular and long-running series. In 2006, he voiced a police officer (Keiji) in Death Note, a Patriot member in Gintama, a student (Tomochika Sakyo) in Ouran High School Host Club, and an Akuma C in D.Gray-man. Around the same period, he also contributed to major titles like The Girl Who Leapt Through Time and the film adaptation of Silver Fang -The Armored Troopers-. In 2007 and 2008, he voiced multiple Gunmen characters in the mecha series Gurren Lagann and its subsequent film adaptation. Additional anime appearances include roles in RD Sennou Chousashitsu, Mouryou no Hako, Antique Bakery, Jigoku Shoujo Futakomori, and Emma: A Victorian Romance. He also contributed to the Japanese dub of the Korean animated film Yobi, The Five Tailed Fox.

Beyond his work in animation, Kobayashi performed the theme song for the television series Senkaiden Houshin Engi.