John Holmes Jenkins III (1940–1989) was an American historian, antiquarian bookseller, publisher, and poker player. Jenkins published his first book the year he graduated from high school. He went on to become a well-known dealer in antiquarian books and documents, primarily of Texas history. Unlike many booksellers, he read much of what he bought and sold, resulting in his ten-volume Papers of the Texas Revolution. His Jenkins Publishing Company, including the Pemberton Press for trade publishing and the San Felipe Press for private publishing, produced more than 300 titles.
Jenkins was killed on April 16, 1989, by a shot to the back of his head, near Bastrop, Texas, while doing field research as part of his work on a biography of Edward Burleson, which was published posthumously, coauthored and completed by Kenneth Kesselus, a Texas historian and first cousin of Jenkins. Although shot in the back of the head, the sheriff declared it a suicide, claiming he somehow disposed of the gun which was never found.