Sam Bard Treiman (/ˈtriːmən/; May 27, 1925 – November 30, 1999) was an American theoretical physicist who produced research in the fields of cosmic rays, quantum physics, plasma physics, and gravity physics. He made contributions to the understanding of the weak interaction and he and his students are credited with developing the so-called standard model of elementary particle physics. He was a Higgins professor of physics at Princeton University, a member of the National Academy of Sciences and member of the JASON Defense Advisory Group. He was a student of Enrico Fermi and John Alexander Simpson Jr. Treiman published articles on quantum mechanics, plasmas, gravity theory, condensed matter and the history of physics.