James P. C. Southall (1871-1962) was an American physicist, professor at Columbia University (1914 to 1940), and specialist in optics.
From 1901 to 1914, he taught at Alabama Polytechnic Institute, and in 1914 he joined the faculty at Columbia University, where he served until his retirement in 1940.
He wrote Principles of Geometrical Optics in 1910 and Mirrors, Prisms and Lenses (1918, rev.
Fifteen of his articles were published in JOSA on such topics as ray tracing, conjugate surfaces and the early pioneers in physiological optics.
In retirement, he returned to Charlottesville and the University of Virginia, and donated most of his books and papers to the library there.