Lyman is a census-designated place (CDP) in Harrison County, Mississippi, United States.

[2] Lyman was once home to an express mail office, saw mill, and general store.

[5] The United States Fish and Wildlife Service operated a fish hatchery in Lyman until 1973, when the Mississippi Department of Wildlife, Fisheries, and Parks took over operations of the fisheries station.

[8] As of the 2020 United States census, there were 2,372 people, 835 households, and 595 families residing in the CDP.

16.6% of all households were made up of individuals, and 5.2% had someone living alone who was 65 years of age or older.