Within its southwestern native range, Ameiurus nebulosus (Brown Bullhead) had been found in the Red River drainage within Oklahoma, Arkansas, and Louisiana but not Texas. We report for the first time the occurrence of Brown Bullhead within the Cypress River system of Texas, a tributary of the Red River. We tentatively conclude that the Cypress River system of Texas is within the natural range of Brown Bullhead, but we cannot exclude human introduction as a possible mechanism for its occurrence, given that Brown Bullhead are introduced worldwide.