Leonard Gross (born February 24, 1931) is an American mathematician and Professor Emeritus of Mathematics at Cornell University.

[3] Gross taught at Yale University and was awarded a National Science Foundation Fellowship in 1959.

Gross's earliest mathematical works[8] were on integration and harmonic analysis on infinite-dimensional spaces.

These ideas, and especially the need for a structure within which potential theory in infinite dimensions could be studied, culminated in Gross's construction of abstract Wiener spaces[9] in 1965.

Gross's logarithmic Sobolev inequalities proved to be of great significance well beyond their original intended scope of application, for example in the proof of the Poincaré conjecture by Grigori Perelman.

Since 2013, Gross and Nelia Charalambous have made a deep study of the Yang–Mills heat equation[18] and related questions.