Nikolai V. Ivanov (, born 1954) is a Russian mathematician who works on topology, geometry and group theory (particularly, modular Teichmüller groups). He is a professor at Michigan State University.
He obtained his Ph.D. under the guidance of Vladimir Abramovich Rokhlin in 1980 at the Steklov Mathematical Institute.
Among his contributions to mathematics are his classification of subgroups of surface mapping class groups, and the establishment that surface mapping class groups satisfy the Tits alternative.
He is a fellow of the American Mathematical Society since 2012.
He is the author of the 1992 book Subgroups of Teichmüller Modular Groups.