Mantarō, Mantaro or Mantarou (written: 萬太郎 or 万太郎) is a masculine Japanese given name. Notable people with the name include:
* (1932–1987), Japanese linguist and sinologist
* (1889–1963), Japanese writer, playwright and poet
Fictional characters:
*, protagonist of the manga series ''Kinnikuman Nisei''
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Japanese masculine given names