Georgy Feodosevich Voronoy (Ukrainian: Георгій Феодосійович Вороний ;Russian: Гео́ргий Феодо́сьевич Вороно́й; 28 April 1868 – 20 November 1908) was a famous Russian mathematician. Among other things, he defined the Voronoi diagram.

Voronoy was born in the village of Zhuravki, district of Pyriatin, in Chernigov Governorate of the Russian Empire (now Varvins'ky region, Poltava Oblast, Ukraine).

From 1889 on Voronoy studied at Saint Petersburg University, where he was a student of Andrey Markov. In 1894 he defended his master's thesis, titled About algebraic integers depending on the roots of an equation of third degree. In the same year Voronoy became professor at the University of Warsaw, where he worked on continued fractions. In 1897 he defended his doctoral dissertation, titled About a generalisation of a continuous fraction.

Voronoy died after a severe disease in his home village, on November 20, 1908.

Among his students were Boris Delaunay (Ph.D. at Kiev University), and Wacław Sierpiński (Ph.D. at Jagiellonian University in 1906). In 2008 Ukraine released two-hryvnia coins commemorating the centenary of Voronoy's death.