Carlos Graef Fernández (February 25, 1911 – January 13, 1988) was a Mexican physicist and mathematician.
A graduate of the National Autonomous University of Mexico (UNAM) and the Massachusetts Institute of Technology (MIT), he was a founding member of the Mexican Mathematical Society and the Mexican Physical Society.
He helped to establish the Tonantzintla Observatory and he later directed it.
He received the National Prize for Arts and Sciences in 1970.