Abbas Bahri (1 January 1955 – 10 January 2016) was a Tunisian mathematician. He was the winner of the Fermat Prize and the Langevin Prize in mathematics. He was a professor of mathematics at Rutgers University. He mainly studied the calculus of variations, partial differential equations, and differential geometry. He introduced the method of the critical points at infinity, which is a fundamental step in the calculus of variations.