Ko Reibun (孔 令文, Japanese: Kō Reibun, Chinese Pinyin: Kǒng Lìngwén, formerly Nie Yuncong, born September 24, 1981) is a Nihon Ki-in professional Go player from China.
He was a student of famous amateur Go schoolmaster Kikuchi Yasuro, World Amateur Go Champion.
Ko reached 2-dan in 2000 and was promoted 7 dan from 2012-02-01. His parents are Nie Weiping and Kong Xiangming. Ko is Japanese by naturalisation.
He is married to Kobayashi Sayaka, daughter of Kobayashi Satoru 9p.
Ko Reibun was go advisor for the Chinese movie Tokyo Newcomer(初到东京), playing from March 2012 in China. The movie tells the story of a Chinese go prodigy who moves to Japan.