Magnus Rudolph Hestenes (February 13, 1906 – May 31, 1991) was an American mathematician best known for his contributions to calculus of variations and optimal control.

[1] As a pioneer in computer science, he devised the conjugate gradient method, published jointly with Eduard Stiefel.

His dissertation was titled "Sufficient Conditions for the General Problem of Mayer with Variable End-Points."

After teaching as an associate professor at Chicago, in 1947 he moved to a professorship at UCLA.

While a professor, Hestenes supervised the thesis research of 34 students, among them Glen Culler, Richard Tapia and Jesse Wilkins, Jr. Hestenes received the Guggenheim (1954) and Fulbright awards, was a vice president of the American Mathematical Society, and was an invited speaker at the 1954 International Congress of Mathematicians in Amsterdam.