Gert Sabidussi (born 28 October 1929 in Graz) is an Austrian mathematician specializing in combinatorics and graph theory.
Sabidussi was born in Graz, Austria. His family later moved to Innsbruck where his father was a Protestant deacon. He graduated from the University of Vienna, where he attended lectured by Felix Ehrenhaft, Nikolaus Hofreiter, Johann Radon and Hans Thirring. In 1953, he defended his doctorate on 0-1 matrices under the supervision of Edmund Hlawka and received a two year fellowship at Princeton University. He was then an Instructor at University of Minnesota in Minneapolis, but because of the heavy teaching load moved a year later, in 1956, to Tulane University in New Orleans. He moved to Montreal in 1963, and was instrumental in bringing to Canada a number of combinatorialists and graph theorists, including Anton Kotzig, and Jaroslav Nešetřil who wrote a thesis under Sabidussi. He first worked at McMaster University and then at University of Montreal. Over the years, he had 13 graduate students. His 60th, 70th and 80th birthdays were celebrated with large Graph Theory birthday conferences.
Sabidussi wrote foundational work on Cayley graphs, graph products and Frucht's theorem.