Caecincola cookorum n. sp. is described from the intestine of white crappie (Pomoxis annularis) collected from B. A. Steinhagen Reservoir in Tyler County, Texas, U.S.A. Worms of the new species possess ceca that extend past the posterior testis, whereas members of the other species in the genus (Caecincola autumnae, Caecincola latostoma, Caecincola longiscens, Caecincola parvulus, and Caecincola wakullata) have ceca that terminate before the end of the posterior testis. This is the second species of Caecincola described from white crappie from rivers draining into the Gulf of Mexico (C. longiscens from Mississippi being the other), and it is possible that a large fraction of the species-level diversity in this genus remains to be discovered.