Frank Bennington Gill (October 2, 1941 in New York City) is an American ornithologist with worldwide research interests and birding experience. He is perhaps best known as the author of the textbook Ornithology (4th edition, 2019), the leading textbook in the field. Gill was raised in Teaneck, New Jersey. He reported that he became interested in birds at the age of seven, when his grandfather, Frank Rockingham Downing, showed him a song sparrow at a birdbath. This was the first time he had seen a bird through binoculars, "and I was hooked."