Slovensko:
Raziskovalno področje Sandija Klavžarja je diskretna matematike ter njene uporabe na drugih področjih. Osrednje teme njegovih raziskav so grafovski produkti, metrična teorija grafov, grafovske invariante, kemijska teorija grafov, teorija Hanojski stolpov ter grafovski algoritmi. Sam in s soavtorji je objavil preko 150 znanstvenih člankov in znanstvene monografije (1) W. Imrich, S. Klavžar, Product Graphs, Wiley-Interscience, New York, 2000 (2) W. Imrich, S. Klavžar, D.F. Rall: Topics in Graph Theory, A K Peters, Wellesley, Massachusetts, 2008 (3) R. Hammack, W. Imrich, S. Klavžar, Thandbook of Product Graphs, CRC Press, Boca Raton, FL, 2011. Je član uredniških odborov številnih znanstvenih revij, med drugim Discrete Applied Mathematics in European Journal of Combinatorics. Soorganiziral je številne mednarodne konference in bil vabljeni in plenarni predavatelj na mnogih mednarodnih konferencah. Pod njegovim mentorstvom je do sedaj doktoriralo 11 študentov. Objavil je številne strokovne in poljudne članke ter univerzitetne učbenike in priročnike. Bil je predstojnik Oddelka za matematiko na Pedagoški fakulteti, UM, član senata iste fakultete ter član senata Fakultete za naravoslovje in matematiko, UM. V letih 2003-2007 je bil predstojnik Oddelka za matematiko na IMFM v Ljubljani, med letoma 2007 in 2010 je bil strokovni vodja na IMFM. Od leta 2010 je predsednik Društva matematikov, fizikov in astronomov Slovenije in od leta 2011 tudi podpredsednik International Academy of Mathematical Chemistry. Sandi Klavžar je leta 2000 je prejel Zoisovo priznanje za pomembne dosežke na področju teorije grafov, leta 2007 pa Zoisovo nagrado za vrhunske znanstvene in razvojne dosežke na področju matematike.

English:
The research interest of Sandi Klavžar is discrete mathematics and its applications. Topics include products of graphs, metric graph theory, graph invariants, chemical graph theory, Tower of Hanoi problems, and graph algorithms. He has published more than 150 scientific papers and the books (1) W. Imrich, S. Klavžar, Product Graphs, Wiley-Interscience, New York, 2000 (2) W. Imrich, S. Klavžar, D.F. Rall: Topics in Graph Theory, A K Peters, Wellesley, Massachusetts, 2008 (3) R. Hammack, W. Imrich, S. Klavžar, Thandbook of Product Graphs, CRC Press, Boca Raton, FL, 2011. He is a member of numerous editorial boards including Discrete Applied Mathematics and European Journal of Combinatorics. He has co-organized many international conferences and gave invited and plenary talks at numerous international conferences. He has supervised 11 Ph.D. students. He has published numerous professional articles, popularization articles, and university textbooks. He was a Department Head of the Department of Mathematics, Faculty of Education, UM, Department Head of the Department of Mathematics at the IMFM Ljubljana and a Member of the Senate at the PeF and FNM, University of Maribor. Between 2007 and 2010 he was the Expert Leader at the IMFM. Since 2010 he is the president of the Society of Mathematicians, Physicists and Astronomers of Slovenia and since 2011 also a Vice-President of the International Academy of Mathematical Chemistry. Sandi Klavžar received in 2000 the Slovenian national award (Zoisovo priznanje) for important scientific achievements in the area of graph theory and in 2007 the Slovenian national award (Zoisovo nagrado) for highest achievements in mathematics.