Peter Carruthers (1935 – August 3, 1997) was an American physicist best known for leading the theoretical division of Los Alamos National Laboratory from 1973 until 1980.
While there he supervised PhD students and post-doctoral fellows until retiring from the position in 1973, when he became the leader of the theoretical division at Los Alamos Laboratory.
While there he oversaw the growth of the laboratory and developed an internationally renowned programme which focused on wide-ranging fundamental research.
In 1980 he stepped down from this position but remained at Los Alamos until 1986, becoming a senior fellow and leader of the Elementary Particle and Field Theory Group.
Together with Murray Gell-Mann and others he played a role in the creation of the Santa Fe Institute.