Ryōhei Arai is a Japanese voice actor affiliated with the talent agency Aoni Production. He was born on September 1 in Saitama Prefecture and is a graduate of the Amusement Media Academy, which he completed in 2012.

Arai has built a career with a steady roster of supporting and leading roles in anime and video games. He is perhaps best known for his performance as Willem Kmetsch, the main protagonist of the fantasy series WorldEnd, as well as for playing Toshiie "Toshi" Homura in Battle Spirits: Burning Soul. One of his more prominent and recent roles is Tasuku Kuresawa, a close friend of the main character in the popular boys' love series Sasaki and Miyano, a role he reprised for the film Sasaki and Miyano: Graduation.

His other major anime roles include Leo Fourcade in the original net animation (ONA) series Tales of Luminaria the Fateful Crossroad, which adapts the mobile role-playing game Tales of Luminaria. He also voiced Dorgon in Lance N' Masques, Shinsho Koganei in Augmented Reality Girls Trinary, and Ryūji Saeki in the third season of World Trigger. Arai has participated in long-running series as well, with appearances such as Charlotte Newichi in One Piece and Hound Asterion in the CGI reboot Saint Seiya: Knights of the Zodiac - Battle for Sanctuary - Part 2.

In video games, he is known for providing the voice of Leo Fourcade in the original Tales of Luminaria, as well as contributions to titles like the Samurai Warriors series and Toukiden. His work has seen a recurring collaboration, as his English-language counterpart for the role of Leo Fourcade in the Tales of Luminaria adaptation was provided by Aaron Dismuke.