Ryo Naitou is a Japanese voice actor and stage performer born on June 22, 1974, in Osaka Prefecture. After graduating from the Osaka branch of the Yoyogi Animation Academy, he began his professional career in the mid-1990s. He is currently affiliated with the talent agency OgiPro THE NEXT. In addition to his voice work, Naitou has maintained a connection to stage acting as a former member of the theater group Alter Ego.

Naitou has built a extensive career through numerous supporting roles across a wide variety of anime series. He is well known for voicing Touta Matsuda in the Death Note franchise, including the television anime and the compilation films Death Note Relight - Visions of a God and Death Note Relight 2 - L's Successors. Another significant role is Taiga Okajima in the Assassination Classroom series, which encompasses the television anime, the film Assassination Classroom the Movie: 365 Days' Time, and the spin-off series Koro Sensei Quest!. His other notable credits include Rei Sagami in Kodocha, Homura in GA: Geijutsuka Art Design Class, and various characters in the Transformers franchise, such as Counter Arrow and Gusher in Transformers: Robots in Disguise. He has also voiced roles in The Asylum Session as Owner, Good Morning Call as Jun Abe, and The Everyday Tales of a Cat God as Gen and the Supermarket president. Early in his career, he took on the role of Afro in Sexy Commando Gaiden: Sugoi yo!! Masaru-san.

Throughout his career, Naitou has demonstrated versatility, often playing a broad spectrum of characters, from少年 to middle-aged men, and is known for creating distinct voices for each role. He has been a recurring presence in the works of directors like大地丙太郎 and樱井弘明. He is also recognized for his long-standing association with the long-running comedy series Gag Manga Biyori (Gyagu Manga Biyori), where he has voiced numerous characters including the poet Matsuo Basho. His performance as金色小春 in The Prince of Tennis series is another example of a character he has played across multiple OVAs and sequels. Naitou's skills extend to voicing characters in video games and radio dramas, and he is proficient in his native Kansai dialects, including Osaka-ben and Kobe-ben.