Ryūho Nagaoka is a Japanese voice actor affiliated with the agency 81 Produce. He was born on February 10, 1999, in Hyōgo Prefecture, Japan. He stands 181cm tall and has blood type B. He is a graduate of Yoyogi Animation Academy and speaks the Kansai dialect. His hobbies and special skills include singing, dancing, and acrobatics.

Nagaoka began his voice acting career in the 2010s and officially joined 81 Produce in October 2022. He has built a diverse portfolio of anime, game, and dubbing roles, often appearing in supporting and guest capacities across numerous popular series.

In addition to the roles specified in the search, Nagaoka's career includes a wide range of anime television series. He has had roles in productions such as High Card, The iDOLMSTER Million Live, Undead Unluck, Ragna Crimson, The Apothecary Diaries, Delicious in Dungeon, Solo Leveling, and Wind Breaker. His more recent and recurring roles include parts in Blue Miburo, Honey Lemon Soda, From Bureaucrat to Villainess: Dad's Been Reincarnated!, I'm Living with an Otaku NEET Kunoichi, and Anyway, I'm Falling in Love with You. He also appears in the web anime Rising Impact.

Of the four roles mentioned in the search query, voice acting work for three of them can be confirmed. He plays the role of Narushi Sukayu in the series Binan Kōkō Chikyū Bōei-bu Haikara!. He plays the role of Rintarō Kai in the series Tamon’s B-Side. He also plays the role of Linx Laulot in the series The Ossan Newbie Adventurer. However, no information could be found to confirm that Ryūho Nagaoka plays the role of Mahan in a series titled Dark Moon: The Blood Altar.

Beyond television animation, Nagaoka has an extensive list of video game credits. He has provided voices for characters in games including Heaven Burns Red, Unicorn Overlord, Library of Ruina, 18TRIP, and Fire Emblem Heroes. In the mobile game Project SEKAI COLORFUL STAGE feat. Hatsune Miku, he voiced a character in 2025.

He is also active in other media, such as digital comics, stage plays, and radio. He was the 125th monthly guest on the radio program Monthly New Male Charm. In 2025, he participated in a BL reading play titled BIBLIOTHEQUE and a reading play of The Rose of Versailles.