David Jonathan Gross (born February 19, 1941 in Washington, D.C.) is an American physicist and string theorist. Along with Frank Wilczek and David Politzer, he was awarded the 2004 Nobel Prize in Physics for his discovery of asymptotic freedom.

In 1973, Gross, working with his first graduate student, Frank Wilczek, at Princeton University, discovered asymptotic freedom, which holds that the closer quarks are to each other, the less the strong interaction (or color charge) between them; when quarks are in extreme proximity, the nuclear force between them is so weak that they behave almost as free particles. Asymptotic freedom, independently discovered by David Politzer, was important for the development of quantum chromodynamics.

Gross, with Jeff Harvey, Emil Martinec, and Ryan Rohm also discovered heterotic string.

Gross received his bachelor's degree and master's degree from the Hebrew University of Jerusalem, Israel, in 1962. He received his Ph.D. in physics from the University of California, Berkeley in 1966 and was a Junior Fellow at Harvard University and a Professor at Princeton University until 1997. He is the recipient of a MacArthur Foundation Fellowship in 1987, the Dirac Medal in 1988, and currently is the director and holder of the Frederick W. Gluck Chair in Theoretical Physics at the Kavli Institute for Theoretical Physics of the University of California, Santa Barbara.