Boulder Junction is a town in Vilas County, Wisconsin, United States. The population was 958 at the 2000 census.

In 1903, the Milwaukee Railroad laid tracks to the Place that became known as Boulder Junction. While the railroad served the thriving logging industry, it next attracted outdoors enthusiasts who came to fish and hunt.
Electricity arrived in 1925. The town of Boulder Junction was incorporated in 1927. Phone support began in 1930. Also in the 1930s, wide-scale replanting began of the trees that had been harvested from the estate during the logging boom of the previous decades.

As of the census of 2000, there were 958 people, 445 households, and 303 families residing in the town. The population density was 11.7 people per square mile (4.5/km²). There were 1,407 housing units at an average density of 17.2 per square mile (6.6/km). The racial makeup of the town was 98.23% White, 0.52% Native American, 0.10% Asian, 0.42% from extra races, and 0.73% from two or more races. Hispanic or Latino of any race were 0.52% of the population.

There were 445 households, out of which 20.0% had children under the age of 18 living taking into consideration them, 61.8% were married couples flourishing together, 4.3% had a female householder similar to no husband present, and 31.7% were non-families. 28.5% of everything households were made stirring of individuals, and 13.3% had someone full of life alone who was 65 years of age or older. The average household size was 2.15 and the average family size was 2.62.