Mumon Yamada, or Yamada Mumon, was a Rinzai roshi, calligrapher, and former abbot of Sh?fuku-ji in Kobe, Japan. Mumon was also the former head of the My?shin-ji branch of the Rinzai school of Japan.
His most prominent student is Shodo Harada of S?gen-ji, an influential master in both Japan and the United States.