Ralston is a census-designated place (CDP) in Park County, Wyoming, United States. The population was 280 at the 2010 census.
Ralston is located at 44°42′52″N 108°52′32″W (44.714544, -108.875598).
According to the United States Census Bureau, the CDP has a total area of 5.6 square miles (14.6 km2), all land.
Ralston post office was established March 16, 1907.
As of the census of 2000, there were 233 people, 96 households, and 74 families residing in the CDP. The population density was 41.3 people per square mile (16.0/km2). There were 101 housing units at an average density of 17.9/sq mi (6.9/km2). The racial makeup of the CDP was 95.71% White, 1.29% Native American, 2.58% from other races, and 0.43% from two or more races. Hispanic or Latino of any race were 6.44% of the population.
There were 96 households, out of which 20.8% had children under the age of 18 living with them, 68.8% were married couples living together, 7.3% had a female householder with no husband present, and 22.9% were non-families. 17.7% of all households were made up of individuals, and 8.3% had someone living alone who was 65 years of age or older. The average household size was 2.43 and the average family size was 2.70.
In the CDP, the population was spread out, with 19.3% under the age of 18, 5.2% from 18 to 24, 24.0% from 25 to 44, 31.8% from 45 to 64, and 19.7% who were 65 years of age or older.