Big Piney is a town in Sublette County, Wyoming, United States. The population was 408 at the 2000 census.
Big Piney is the oldest settlement in Sublette County. It was founded in 1879, when rancher Daniel B. Budd and his partner Hugh McKay came with a thousand head of cattle from Nevada hoping to ship them, but got caught instead in severe winter weather in the Green River Valley. The following year, Dan Budd relocated his family to what is now known as Big Piney.
Known as the "Ice Box of the Nation," Big Piney has one of the coldest climates among inhabited locations in the Lower 48. Big Piney experiences a semi-arid climate (Köppen BSk) with long, cold, dry winters and short, warm summers. Because of the high elevation and aridity, large diurnal temperature differences are a regular feature of Big Piney's climate. Precipitation is very low and somewhat heavily concentrated in the warmer months.
There were 161 households out of which 34.2% had children under the age of 18 living with them, 62.7% were married couples living together, 5.0% had a female householder with no husband present, and 29.8% were non-families. 27.3% of all households were made up of individuals and 6.8% had someone living alone who was 65 years of age or older. The average household size was 2.53 and the average family size was 3.12.
Public education in the town of Big Piney is provided by Sublette County School District #9. Schools serving the town include Big Piney Elementary School (grades K-5), Big Piney Middle School (grades 6-8), and Big Piney High School (grades 9-12).