Lissorchis amniculensis n. sp. is described from the small intestine of creek chubsuckers collected from a small tributary stream of Big Sandy Creek in the Big Sandy Creek Unit of the Big Thicket National Preserve, Polk County, Texas, U.S.A. Members of the new species possess a distinct trilobed ovary, a feature found in individuals of 9 other species of Lissorchis. The new species is distinguished from these species by possessing a bipartite seminal vesicle with the distal portion larger than the proximal portion, vitelline follicles that extend beyond the posterior extent of the testes, a small posttesticular space, and a single dextral uterine loop that originates from the posttesticular space.