Williston Mill Historic District is a national historic district in Denton, Caroline County, Maryland, in the United States. It consists of two historic structures—a grist mill and a miller's house—which share the acreage with the mill stream and race that empties into Mill Creek, a tributary of the Choptank River. The Williston miller's house is a two-story, four-bay single-pile frame dwelling, built originally between 1840 and 1850 with later 19th century expansions. The mill building dates from around 1830–1840, with the two-story section built around 1895. It is one of two grist mills that remain standing in Caroline County.[2]