Paul Hevener DeBach (28 December 1914 – 15 February 1992) was an American entomologist who was a specialist on biological control.
DeBach was born in Miles City, Montana but grew up in Southern California after his parents moved there.
He continued studies at Riverside in the Citrus Experiment Station under Harry Scott Smith and received a Ph.D. in 1940 on biological control.
He returned to the Citrus Experiment Station at Riverside after World War II and worked there until retirement in 1983.
He attempted to provide theoretical bases for the evaluation and choice of biological control agents.