Daiki Kobayashi is a Japanese male voice actor and singer affiliated with the agency 81 Produce. He was born on September 23, 1991, in Osaka Prefecture. His inspiration to pursue voice acting came from watching the television program Oha Suta, where he learned that the host, Koichi Yamadera, also voiced characters in the show's anime segments. This interest grew during his中学 years when he began watching late-night anime. After spending about half a year at a voice acting training school in Osaka during high school, he went on to graduate from the Human Academy and the 81 Actor's Studio. He officially joined 81 Produce as a junior member on April 1, 2014.

Kobayashi's early career consisted of minor roles in series such as ReLIFE and Mobile Suit Gundam: Iron-Blooded Orphans. His first major breakthrough came in 2016 when he was cast as Niko in the anime Nanbaka. That same year, he began voicing the cross-dressing male idol Saki Mizushima in The Idolmaster SideM, a role that brought him significant attention and for which he has been praised for his androgynous vocal quality.

In the following years, Kobayashi built a diverse portfolio of roles. In 2017, he voiced Steve Kanamori in 100% Pascal-sensei and Kaoru Yamaguchi in Just Because!. The year 2018 saw him take on the role of Subaru Hoshiyomi in Future Card Buddyfight Ace. He also had recurring roles in the long-running sports anime Captain Tsubasa (2018 version) and Major 2nd.

Kobayashi's role as the titular character in the 2024 anime Kinokoinu - Mushroom Pup, where he voices the mushroom dog Kinokoinu, is a notable lead performance. That same year, he also appeared in Egumi Legacy as Invincible Stalker and Perm Stripe. He has also taken over a role previously held by another actor, voicing Mitsuru Tenma in Ensemble Stars! starting in 2023.

In addition to his voice work in anime, Kobayashi is active in the video game industry. His most prominent game role is Saki Mizushima in The Idolmaster SideM and its related titles, through which he performs music as part of the in-game unit Cafe Parade. Other game credits include the role of Hakuzōsu in the smartphone game Onmyōji.

Kobayashi is known to have a close friendship with fellow voice actor Yoshiki Nakajima, as they were classmates at the voice acting training school and once shared a room together. His personal interests and skills include dancing and playing video games. In November 2025, it was announced that he would be a member of a new Kiramune artist unit called IXIS, marking a significant step in his music career.