Ellis Robert Kolchin (April 18, 1916 – October 30, 1991) was an American mathematician at Columbia University. Kolchin earned a doctorate in mathematics from Columbia University in 1941 under supervision of Joseph Ritt. He was awarded a Guggenheim Fellowship in 1954 and 1961.

Kolchin worked on differential algebra and its relation to differential equations, and founded the modern theory of linear algebraic groups. His doctoral students include Azriel Rosenfeld and Irving Adler.

• Kolchin topology
• Lie–Kolchin theorem
• Picard–Vessiot theory

• Kolchin, E. R. (1985), Differential algebraic groups, Pure and Applied Mathematics, vol. 114, Boston, MA: Academic Press, ISBN 978-0-12-417640-9, MR 0776230
• Kolchin, E. R. (1973), Differential algebra and algebraic groups, Pure and Applied Mathematics, vol. 54, Boston, MA: Academic Press, ISBN 978-0-12-417650-8, MR 0568864
• Kolchin, Ellis (1999), Selected works of Ellis Kolchin with commentary, Providence, R.I.: American Mathematical Society, ISBN 978-0-8218-0542-8, MR 1677530^[1]