William M. Kantor (born September 19, 1944) is an American mathematician who works in finite group theory and finite geometries, particularly in computational aspects of these subjects.

Kantor graduated with a bachelor's degree from Brooklyn College in 1964.

[1] He went on to graduate studies at the University of Wisconsin, receiving his PhD in 1968 under the supervision of Peter Dembowski and R. H.

Algorithms developed by him have found use, for example, in the GAP computer algebra system.

[3] Kantor has written over 170 papers,[4] and has advised 7 PhD students.