De Soto is a census-designated place and unincorporated community in Clarke County, Mississippi, United States. It was first named as a CDP in the 2020 Census which listed a population of 274. De Soto was named after Hernando de Soto. De Soto was one of four principle towns established in Clarke County before the American Civil War. Establis…De Soto is a census-designated place and unincorporated community in Clarke County, Mississippi, United States. It was first named as a CDP in the 2020 Census which listed a population of 274. De Soto was named after Hernando de Soto. De Soto was one of four principle towns established in Clarke County before the American Civil War. Established along the Chickasawhay River before the arrival of the Mobile and Ohio Railroad, construction of housing in De Soto may have started as early as 1845 and by 1858 churches were being erected. The town had a Post Office and two churches in 1900 when the population was 258.