Robert Thomas Hill (August 11, 1858 – July 20, 1941) was a significant figure in the development of American geology during the late nineteenth century and in the early part of the twentieth century.
As a pioneer Texas geologist, Hill discovered and named the Comanche Series of the Lower Cretaceous, and was a lifelong student of the structure and stratigraphy of the Cretaceous deposits of Central Texas and neighboring regions.