The article presents the person and works of Georgy Voronoi (1868-1908), the inventor of an original method of diagrams, a student of the famous mathematician Andrey Markov. Georgy Voronoi graduated from the Department of Physics and Mathematics at the University of St. Petersburg, and subsequently worked as a professor of mathematics at the Imperial University of Warsaw. One of his students was the future outstanding Polish mathematician Wacław Sierpiński. In his brief lifetime G. Voronoi published several important scientific articles on number theory. In an almost 100 page paper in French published in 1908 he described a method of diagrams, or polygons, which became known as the method of Voronoi diagrams. In the digital age this method and its modifications found new applications. The entry “Voronoi” is getting more popular on the Internet, and the method of Voronoi diagrams and its modifications are widely described in handbooks and scientific articles. The article presents application of the method in the most popular computer programs from the Geographic Information System (GIS) group and presents examples of its usage in research on geographic space in various scientific disciplines.