Ryohei Yamanaka (山中 亮平, Yamanaka Ryohei, born 22 June 1988 in Osaka Prefecture) is a Japanese rugby union player who plays as a fly-half or centre.He currently plays for Japanese club Kobelco Steelers.

[1][2] In 2011, Yamanaka received a 2 year ban from the IRB for rubbing a cream on his upper lip - in an attempt to promote moustache growth - which contained a banned steroid, either methyltestosterone or methandriol.

[4][5] He was also named in the first ever Sunwolves squad which will compete in Super Rugby from the 2016 season.

[6] Yamanaka is a Japanese international who debuted against the Arabian Gulf in 2010, but did not make the squad for either the 2011 or 2015 Rugby World Cups.

[1] On 19 September 2023, Yamanaka was called up to Japan's Rugby World Cup squad as an injury replacement for Semisi Masirewa.