Basin is a town in, and the county seat of, Big Horn County, Wyoming, United States. The population was 1,239 at the 2000 census. The community is located near the center of the Bighorn Basin with the Big Horn River east of the town. Basin's post office, built in 1919, is listed on the National Register of Historic Places.
In the town the population was spread out with 20.1% under the age of 18, 5.5% from 18 to 24, 19.6% from 25 to 44, 27.9% from 45 to 64, and 26.9% who were 65 years of age or older. The median age was 48 years. For every 100 females there were 90.8 males. For every 100 females age 18 and over, there were 86.6 males.
The median income for a household in the town was $33,519, and the median income for a family was $42,768. Males had a median income of $33,942 versus $20,139 for females. The per capita income for the town was $17,890. About 6.1% of families and 11.6% of the population were below the poverty line, including 17.5% of those under age 18 and 12.7% of those age 65 or over.
The Wyoming Department of Health Wyoming Retirement Center, a nursing home, is located in Basin. The facility was operated by the Wyoming Board of Charities and Reform until that agency was dissolved as a result of a state constitutional amendment passed in November 1990.
The United States Postal Service operates the Basin Post Office.
Public education in the town of Basin is provided by Big Horn County School District #4. The district has four campuses – Laura Irwin Elementary School (grades K-4), Manderson Elementary School (grade 5), Cloud Peak Middle School (grades 6-8), and Riverside High School (grades 9-12)