Igor Dmitriyevich Novikov (Russian: И́горь Дми́триевич Но́виков) is a Russian (and former Soviet) theoretical astrophysicist and cosmologist.

Novikov put forward the idea of white holes in 1964. He also formulated the Novikov self-consistency principle in the mid-1980s, a contribution to the theory of time travel.

Novikov gained his Ph.D. degree in astrophysics in 1965 and the Russian D.Sc. degree in astrophysics in 1970. From 1974 to 1990 he was head of the Department of Relativistic Astrophysics at the Russian Space Research Institute in Moscow. Before 1991 he was head of the Department of Theoretical Astrophysics at the Lebedev Physical Institute in Moscow and has been professor at Moscow State University. Since 1994 he has been director of the Theoretical Astrophysics Center (TAC) of the University of Copenhagen, Denmark. He is currently also a professor of astrophysics at the Observatory of the University of Copenhagen, where he has been since 1991. Since 1998 he has been a Fellow of the Royal Astronomical Society.