Ryōichi, Ryoichi or Ryouichi (written: 良一, 遼一, 僚一, 亮一 or 了一) is a masculine Japanese given name. Notable people with the name include:
Ryoichi Fujisawa (藤沢 良一) (born 1927), Japanese Nordic combined skier
Ryoichi Fukushige (福重 良一) (born 1971), Japanese footballer
Ryōichi Hattori (服部 良一) (1907–1993), Japanese composer
Ryoichi Hattori (politician) (服部 良一) (born 1950), Japanese politician
Ryoichi Ikegami (池上 遼一) (born 1944), Japanese manga artist
Ryoichi Jinnai (神内 良一) (born 1926), Japanese businessman
Ryoichi Kawakatsu (川勝 良一) (born 1958), Japanese footballer and manager
Ryoichi Kimizuka (君塚 良一) (born 1958), Japanese screenwriter, television director and film director
Kinoshita Ryoichi (木下 良一) (born 1959), Japanese aikidoka
Ryoichi Kurisawa (栗澤 僚一) (born 1982), Japanese footballer
Ryōichi Kuroda (黒田 了一) (1911–2003), Japanese lawyer and politician
Ryoichi Maeda (前田 遼一) (born 1981), Japanese footballer
Ryoichi Sasakawa (笹川 良一) (1899–1995), Japanese businessman and politician
Ryōichi Sekiya (關家 良一) (born 1967), Japanese ultramarathon runner
Ryōichi Tanaka (田中 亮一) (born 1947), Japanese voice actor
Ryōichi Yazu (矢頭 良一) (1878–1908), Japanese inventor
