Efficient targeting of limited conservation resources requires a consistent understanding of the distribution and habitat needs of populations of concern. Both Louisiana and Texas Seaside Sparrows (Ammospiza maritima fisheri and A. m. sennetti, respectively) occur along the Texas coast, but confusion remains about the geographic distribution and status of Texas Seaside Sparrows. Given there has been relatively little attention focused on Seaside Sparrows in Texas since Griscom's “Notes on Texas Seaside Sparrows” (1948), we provide here an update to (1) clarify the status of Seaside Sparrows as year-round, breeding residents south to the Rio Grande; (2) highlight important differences in the habitats used by Seaside Sparrows across the Texas coast; and (3) expand on previous population genetic analyses by incorporating additional samples. The current understanding of the population biology of Seaside Sparrows in southern Texas is insufficient for developing sound conservation strategies: the southernmost populations of Texas Seaside Sparrows are small, isolated, and occupy a unique habitat with a limited distribution. Additional information regarding the distribution, population size, and demographic trends of these populations is needed.