Hugo Peter Kortschak (or Kortschack; 4 September 1911, in Chicago, Illinois – 20 August 1983) was an American biologist who discovered the C4 pathway in 1957. This pathway is an adaptation found in plants which reduces loss of energy via the inefficient C2 pathway. It is found in several plants, such as maize and sugarcane. The C4 pathway was rediscovered by Marshall Hatch and Roger Slack (to whom the discovery is sometimes wrongly credited). He was the son of the Austrian-American violinist Hugo Kortschak, father of Alice M Kortschak and Nonnie Winifred Kortschak.