Julius Wolff (18 April 1882 in Nijmegen – 8 February 1945 in Bergen-Belsen) was a Dutch mathematician, known for the Denjoy–Wolff theorem and for his boundary version of the Schwarz lemma. Wolff studied mathematics and physics at the University of Amsterdam, where he earned his doctorate in 1908 under Korteweg with thesis Dynamen, beschouwd als duale vectoren. From 1907 to 1917 he taught at secondary and grammar schools in Meppel, Middelburg, and Amsterdam. In 1917 Wolff was appointed Professor of differential calculus, theory of functions and higher algebra at the University of Groningen and in 1922 at the University of Utrecht. He was also a statistical advisor for the life insurance company (or co-operative distributive society) "Eigen Hulp," (a predecessor of AEGON) with offices at The