Yitzhak Katznelson (born 1934) is an Israeli mathematician. Katznelson was born in Jerusalem. He received his doctoral degree from the University of Paris in 1956. He is a professor of mathematics at Stanford University. He is the author of An Introduction to Harmonic Analysis, which won the Steele Prize for Mathematical Exposition in 2002. In 2012 he became a fellow of the American Mathematical Society.