Eugene W. Caldwell (1870–1918) was an American engineer, radiographer, and physician who conducted early work on the medical uses of X-rays. A native of Missouri, Caldwell studied engineering at the University of Kansas. After working as an engineer for five years, Caldwell became interested in X-rays in 1897, opening what may have been the first X-ray clinic in New York City. He taught radiography at University and Bellevue Hospital Medical College and later graduated with a medical degree from that institution.