Sandi Klavžar (born 5 February 1962) is a Slovenian mathematician working in the area of graph theory and its applications.
Klavžar received his Ph.D. from the University of Ljubljana in 1990, under the supervision of Wilfried Imrich and Tomaž Pisanski.
Together with Wilfried Imrich and Richard Hammack, he is the author of the book Handbook of Product Graphs (CRC Press, 2011).
Together with Andreas M. Hinz, Uroš Milutinović, and Ciril Petr, he is the author of the book The Tower of Hanoi – Myths and Maths (Springer, Basel, 2013).
In 2007, Klavžar received the Zois award for exceptional contributions to science and mathematics.