Robert Leslie Usinger (October 24, 1912, Fort Bragg, California – October 1, 1968, San Francisco) was an American entomologist and professor at the University of California, Berkeley and the University of California, Davis. A fellow of the Linnaean Society of London, he served as president of the Entomological Society of America in 1965-1966. He produced over 250 publications, including several popular books, and was known as an expert on the Hemiptera, the "true bugs".