Genzui KOISHI (December 31, 1784 - March 4, 1849) was a Rangakusha (a person who studied Western sciences by means of the Dutch language) and Ranpoi (a person who studied Western medicine by means of the Dutch language) who lived during the late Edo period.
小石元瑞（こいしげんずい、天明4年11月20日(旧暦)（1784年12月31日）-嘉永2年2月10日(旧暦)（1849年3月4日））は、江戸時代後期の蘭学者、蘭方医。