Derek J. Penslar (1958-) is a Canadian historian. He was raised in Los Angeles, attended Stanford University for his first degree, and then took his graduate degrees at the University of California at Berkeley, where his doctoral advisor was Tony Judt. Penslar taught at Indiana University in Bloomington from 1987 to 1998, when he moved to Toronto to assume the Samuel J. Zacks Chair in Jewish History at the University of Toronto (U of T). Between 2002 and 2008 he directed U of T's Centre for Jewish Studies.
Penslar's areas of research expertise include modern European Jewry, Zionism and Israel. Historian Michael Berkowitz calls Penslar "one of the most trenchant [analysts] of how Zionism functioned on the ground in Palestine in the nineteenth and early twentieth centuries."