Samuel R. (Sam) Buss (born August 6, 1957) is an American computer scientist and mathematician who has made major contributions to the fields of mathematical logic, complexity theory and proof complexity.

He joined the University of California, Berkeley, mathematics department in 1986 as a Lecturer, and stayed there until 1988.

In 2019, Buss gave the Gödel Lecture titled Totality, provability and feasibility.

He introduced bounded arithmetic in his thesis and gave a nice proof theoretic characterization of polynomial time computation.

[3] Buss proved in 1983 that the Boolean Formula Evaluation problem is in ALogTime, a major result in complexity theory.