Ellis Robert Kolchin (April 18, 1916 – October 30, 1991) was an American mathematician at Columbia University.

He earned a doctorate in mathematics from Columbia University in 1941 under supervision of Joseph Ritt.

There are few people working in this area who have not benefited enormously through personal contact with him and none who have not been influenced by his publications.

He gave a famous plenary address at the International Congress of Mathematicians in 1966 (Moscow) where he outlined Kolchin's problems a famous collection of unsolved problems in Differential Algebra.

His doctoral students include Azriel Rosenfeld, Irving Adler, and (unofficially) Alexandru Buium.