Ke Zhao or Chao Ko (Chinese: 柯召; pinyin: Kē Zhào; Wade–Giles: K'o Chao, April 12, 1910 – November 8, 2002) was a Chinese mathematician born in Wenling, Taizhou, Zhejiang, People's Republic of China.Ke graduated from Tsinghua University in 1933 and obtained his doctorate from the University of Manchester under Louis Mordell in 1937. His main fields of study were algebra, number theory and combinatorics.