Joseph E. Gillis (Hebrew: יוסף גיליס; 3 August 1911 – 18 November 1993) was a British-Israeli mathematician and one of the founders of the Faculty of Mathematics at the Weizmann Institute of Science, where he served as a professor of Applied Mathematics.
He made notable contributions to fractal sets, fluid dynamics, random walks, and pioneered the combinatorial theory of special functions of mathematical physics.
He studied at Trinity College, Cambridge, completing his doctoral thesis on "Some Geometrical Properties of Linearly Measurable Plane Sets of Points" under A.S. Besicovitch in 1935.
During the Academic Year 1954-1955 he visited the Institute for Advanced Study as part of the Electronic Computer Project headed by John von Neumann.
He was very active in advancing mathematics education, and chaired the department of Science Teaching at the Weizmann Institute.