Robert Harry Kraichnan (January 15, 1928 – February 26, 2008), a resident of Santa Fe, New Mexico, was an American theoretical physicist best known for his work on the theory of fluid turbulence.
Kraichnan received his Ph.D. from MIT, graduating in 1949. He became a member of the Institute for Advanced Study in Princeton in 1949/50, and was one of the last assistants to Albert Einstein.
After his appointment at Princeton, he worked in Columbia University and the Courant Institute of Mathematical Sciences at New York University. From 1962 on, he was supported by research grants and worked as a freelance consultant for the Los Alamos National Laboratory, Princeton University, the Office of Naval Research, the Woods Hole Oceanographic Institution and NASA. He had a keen passion for hiking, so he lived in the mountains of New Hampshires and later in White Rock, New Mexico and eventually to Santa Fe, New Mexico near Los Alamos. In 2003, he returned to academia when he was appointed Homewood Professor in the Whiting School of Engineering at Johns Hopkins University, but by this time he had already fallen ill.