Birgit Vennesland (17 November 1913 — 15 October 2001) was a Norwegian-American biochemist. Vennesland spent the majority of her career as an academic for the University of Chicago from 1941 to 1968. While at Chicago, she compared the enzymes that animals use during metabolism and to the enzymes used by plants in photosynthesis. After leaving Chicago for Germany, Vennesland was the director of the Max Planck Institute for Cell Biology from 1968 to 1970. She later was the director of a eponymous research facility by the Max Planck Society from 1970 until her retirement in 1981. During her career, Vennesland received the Stephen Hales Prize from the American Society of Plant Biologists in 1950 and the Garvan-Olin Medal from the American Chemical Society in 1964.