Benjamin Weiss (January 26, 1937) is an American neuropharmacologist, Emeritus Professor of Pharmacology and Physiology at Drexel University College of Medicine. He is best known for his work with cyclic nucleotide phosphodiesterases. He was the first to propose, based on his experimental work, that selective inhibition of phosphodiesterases which are expressed differentially in all tissues, could be used as a target for drug development. His work is the basis for many marketed and developmental human drugs that selectively inhibit cyclic nucleotide phosphodiesterases.