Thomas Lauritsen (November 16, 1915-October 16, 1973) was an American nuclear physicist best known for his abilities at designing and (with his own hands) building experimental facilities and instrumentation for experimental nuclear physics; and as the longtime co-author of a periodic compilation of nuclear data. Except for brief periods abroad, his career was entirely at the California Institute of Technology, mostly as a professor of physics. In 1969 he was elected as a member of the National Academy of Sciences[1] and also the American Academy of Arts and Sciences.[2]