Ryoko Nagata is a Japanese voice actress and narrator born on February 23, 1975, in Gifu Prefecture. She is a graduate of the University of Tsukuba, where she studied Japanese Language and Culture. Before entering the voice acting industry, Nagata developed a foundation in performance through stage acting and training at the Kinnoka Drama Studio. She was formerly affiliated with the talent agency Vi-vo and later with Atomic Monkey.

Nagata's career in voice acting began in the late 1990s, and she has built a extensive body of work across anime, video games, and dubbing for foreign films and television series. Her versatility allows her to portray a wide range of characters, from young heroines to comedic creatures and maternal figures.

In anime, Nagata is widely recognized for her long-running involvement in the Yo-kai Watch franchise. She voices multiple characters across the series, including Keita's mother, the flamboyant nine-tailed fox Kyubi, the ghost Hanako-san, and the Hikikōmori. She also reprised these roles in the 2014 film Yo-kai Watch: The Movie. Her other notable anime roles include Éclair in Kiddy Grade and its sequel Kiddy Girl-and, Cynthia in Heat Guy J, Noel in Mermaid Melody Pichi Pichi Pitch, and Takako Nakanishi in The Melancholy of Haruhi Suzumiya. She also voiced Ketchup in Magical Play and Naoki Matsudo in the OVA De:vadasy.

Beyond anime, Nagata has lent her voice to numerous video game characters. Her game credits include Rems in Growlanser IV, a player character in InuYasha: The Secret of the Cursed Mask, and roles in the Super Robot Wars and Phantasy Star series.

A significant part of Nagata's career involves voice dubbing for foreign live-action and animated content. She is the regular Japanese voice for actress Ashley Tisdale, dubbing her roles as Maddie Fitzpatrick in The Suite Life of Zack & Cody, Sharpay Evans in the High School Musical film series, and Candace Flynn in the animated series Phineas and Ferb. Her other dubbing credits include Chloe Sullivan in Smallville and the lead role of Hazel Grace Lancaster in The Fault in Our Stars.

In addition to character work, Nagata is active as a narrator for documentaries, news programs, and variety shows. Her narration work has been featured on programs such as NNN Document and has received recognition, including awards from the Japan Commercial Broadcasters Association. She has also made on-camera appearances in children's programming and participates in public朗读 (reading) events, blending her interests in literature and performance.