Jan Drewes Achenbach (20 August 1935 – 22 August 2020) was a professor emeritus (Walter P. Murphy Professor and Distinguished McCormick School Professor) at Northwestern University. Achenbach was born in the northern region of the Netherlands, in Leeuwarden. He studied aeronautics at Delft University of Technology, which he finished with a M.Sc. degree in 1959. Thereafter, he went to the United States, Stanford University, where he received his Ph.D. degree in 1962. After working for a year as a preceptor at Columbia University, he was then appointed as assistant professor at Northwestern University.