Leslie Lawrance Foldy (1919–2001) was a theoretical physicist, who made contributions to condensed matter physics and quantum mechanics.
Foldy was born László Földi in kisszeben, Hungary (today's town of Sabinov, Slovakia), on October 26, 1919.
He started his PHD in 1945 at the University of California in Berkeley, in J. Robert Oppenheimer's group, and with Luis Alvarez and David Bohm, until 1947.
In 1949 at the University of Rochester, Foldy and Siegfried Adolf Wouthuysen, working with Robert Marshak, wrote a preprint on the nonrelativistic limit of the Dirac equation.
In 1950 at Michigan, their work was criticized as erroneous, motivating Foldy and Wouthuysen to make their calculations clear and efficient.