According to the census2 of 2000, there were 20,555 people, 7,993 households, and 5,922 families residing in Teller County. The population density was 14/km² (37/mi²). There were 10,362 housing units at an average density of 7/km² (19/mi²). The racial makeup of the county was 94.92% White, 0.55% Black or African American, 0.97% Native American, 0.58% Asian, 0.08% Pacific Islander, 0.90% from other races, and 2.00% from two or more races. 3.49% of the population were Hispanic or Latino of any race.

There were 7,993 households out of which 33.60% had children under the age of 18 living with them, 64.20% were married couples living together, 6.60% had a female householder with no husband present, and 25.90% were non-families. 19.60% of all households were made up of individuals and 4.00% had someone living alone who was 65 years of age or older. The average household size was 2.56 and the average family size was 2.94.

The median income for a household in the county was $50,165, and the median income for a family was $57,071. Males had a median income of $37,194 versus $26,934 for females. The per capita income for the county was $23,412. 5.40% of the population and 3.40% of families were below the poverty line. 6.90% of those under the age of 18 and 4.20% of those 65 and older were living below the poverty line.

Teller County Neighboring areas include Jefferson County, Douglas County, El Paso County, Fremont County, and Park County. The Cities and towns of this County are Cripple Creek, Victor, Woodland Park, and Divide.