| Sergey Nikolsky | |
| Birth Name: | Sergey Mikhailovich Nikolsky |
| Birth Date: | 30 April 1905 |
| Birth Place: | Talitsa, Kamyshlovsky Uyezd, Perm Governorate, Russian Empire |
| Death Place: | Moscow,[1] Russia |
| Field: | Mathematics |
| Work Institution: | Moscow State University Dnipropetrovsk National University Steklov Institute of Mathematics MIPT |
| Alma Mater: | Dnipropetrovsk National University |
| Doctoral Advisor: | Andrey Kolmogorov |
| Doctoral Students: | Oleg Besov, Petraq Pilika |
| Prizes: | Kolmogorov Prize (2000) |
Sergey Mikhailovich Nikolsky (Russian: Серге́й Миха́йлович Нико́льский; 30 April 1905 – 9 November 2012) was a Soviet and Russian mathematician.
Nikolsky was born in Talitsa, which was at that time located in Kamyshlovsky Uyezd of the Russian Empire. He had been an Academician since 28 November 1972. He also had won many scientific awards. At the age of 92 he was still actively giving lectures in Moscow Institute of Physics and Technology. In 2005, he was only giving talks at scientific conferences, but was still working in MIPT, at the age of 100. He died in Moscow in November 2012 at the age of 107.
Nikolsky made fundamental contributions to functional analysis, approximation of functions, quadrature formulas, enclosed functional spaces and their applications to variational solutions of partial differential equations. He created a large scientific school of functions' theory and its applications. He authored over 100 scientific publications, including 3 monographs, 2 college textbooks and 7 school textbooks.