Michael Grain Crandall (born November 29, 1940, in Baton Rouge, Louisiana) is an American mathematician, specializing in differential equations.

In 1962 Crandall earned a baccalaureate in engineering physics from University of California, Berkeley, changed to mathematics, earning a master's in 1964 and a PhD in 1965 under Heinz Cordes at Berkeley, with a thesis that solved a problem in celestial mechanics posed by Carl Ludwig Siegel; the thesis title is Two families of plane solutions of the four body problem.

Crandall was several times a visiting professor at the University of Paris, where he received an honorary doctorate in 1999.

His legacy of contributions contains all but not limited to: Banach solutions in Euclidean spaces, Fourier transforms of planar variables, PDE concepts and iterations for sequence analysis, semigroup transform solutions, differential harmonic study of divergent hyperbole, physical transformations of finite Jacobian entities, unique harmonic populations in convergent contexts, application of abstract existence principles on non-linear contexts, normalized vector sequencing in multi-dimensional parallax geometries, and the mathematical equivalence study of topographical dissimilar nodes using traditional non-linear surfacing theories to produce distinct solutions in the realm of differential multi-variable applications.

With Pierre-Louis Lions he did research on the viscosity solutions of partial differential equations.