During a study of the endohelminths of wading birds from the Texas Gulf coast, 4 specimens of an undescribed species of Wardianum (Cyclocoelidae: Haematotrephinae) were collected from willets, Catoptrophorus semipalmatus, from the Galveston, Texas, area. Wardianum catoptrophori n. sp. can be distinguished from all the other species in the genus (Wardianum chauhani, Wardianum. facioi, Wardianum lateriovari, Wardianum taxorchis, Wardianum triangulare, and Wardianum wilsoni) by having a pharynx that is wider than long. It can be distinguished from all other species in the genus except W. facioi by having uterine loops that extend laterally beyond the outer margin of the ceca approaching the body wall and that extend posteriorly along the lateral margins of both testes to the level of the posttesticular space but that do not invade the intertesticular space. The new species differs from W. facioi by having a larger body size (14.0 [12.5–16.5] mm long by 3.5 [3.0–4.0] mm wide compared with 6.6–7.5 mm long), a larger ovary (350–450 wide compared with 260–267), smaller eggs (120–130 long by 55–70 wide compared with 134–138 by 71–72), an oral sucker, and W. catoptrophori lacks uterine branches extending between the ovary and the left testis that are present in W. facioi. This is the first report of a species of Wardianum from a species of Catoptrophorus.