Clarkson is an unincorporated community in Milam County, Texas, United States. According to the Handbook of Texas, the community had a population of 10 in 2000. A post office was established at Clarkson in 1889 and remained in operation until 1906. Its population was reported as 50 in the 1940s, a figure which declined to 10 from 1990 through 2000.