Richard Barry Bernstein was an American physical chemist. He is primarily known for his researches in chemical kinetics and reaction dynamics by molecular beam scattering and laser techniques. He is credited with having founded femtochemistry, which laid the groundwork for developments in femtobiology. He was elected a Fellow of the American Academy of Arts and Sciences in 1970. Among his awards were the National Medal of Science and the Willard Gibbs Award, both in 1989.
Bernstein suffered a heart attack in Moscow and died shortly afterwards in Helsinki, Finland, aged 66.