Ryōtarō Okiayu (置鮎龍太郎, born in Kitakyushu on November 17th, 1969) is a Japanese voice actor who provided voices in the Japanese version of Thomas & Friends.
He is best known for voicing Zero and Protoman from the "Mega Man" series, Chocolateman from "Soreike! Anpanman", Rodimus Prime from "Transformers: Energon", Treize Khushrenda from "Mobile Suit Gundam Wing", and Scar from "Fullmetal Alchemist".
- Rheneas (fourth - seventh seasons)
- Troublesome Trucks (A Surprise for Percy)
- The Maithwaite stationmaster (fifth season only)
- A Signalman (Emily's New Coaches)
- Edward's driver (Edward's Brass Band)
- Percy's driver (Percy Gets it Right)
- Duck's driver (Edward the Very Useful Engine)
- Donald and Douglas' drivers (Bad Day at Castle Loch)
- Murdoch's driver (Peace and Quiet)
- Workmen (Busy Going Backwards)
- There Once was an Engine who Ran Away (performed)
- Both he and Salty's Lighthouse voice actor Paul Dobson voiced Rodimus Prime from "Transformers: Energon" in their respective languages.
- Both he and Tatá Guarnieri voiced Tiger's eye from "Sailor's moon" in their respective languages.
- He was formerly married to Nao Nagasawa.
- Both he and Dafnis Fernández voice the title character of "Toriko" in their respective languages.
- He worked alongside Keiji Hirai, Miyu Matsuki, and Tomohisa Asō on "Romeo X Juliet".
- Both he and Shinji Ogawa voiced Hyō from "Fist of the North Star".