| Igor Dolgachev | |
| Birth Date: | 7 April 1944 |
| Nationality: | American |
| Fields: | Mathematics |
| Workplaces: | University of Michigan |
| Alma Mater: | Moscow State University (1966) |
| Thesis Title: | On the purity of the degeneration locus of families of curves |
| Thesis Year: | 1970 |
| Doctoral Advisor: | Igor Shafarevich |
| Known For: | Dolgachev surface |
Igor V. Dolgachev (born 7 April 1944[1]) is a Russian–American mathematician specializing in algebraic geometry. He has been a professor at the University of Michigan since 1978. He introduced Dolgachev surfaces in 1981.[2]
Dolgachev completed his Ph.D. at Moscow State University in 1970, with thesis On the purity of the degeneration locus of families of curves written under the supervision of Igor Shafarevich.