As of the 2000 censusGR2, there were 30,700 people, 11,500 households, and 7,600 families residing in Juneau. The population density was 4.4/km² (11.3/mi²). There were 12,300 housing units at an average density of 1.7/km² (4.5/mi²).

By race Juneau was 75% white, 11% Native American, 5% Asian, 0.8% black, 0.4% Pacific Islander, and 3% Hispanic or Latino of any race. One percent belonged to other races, and 7% to two or more races. 2.61% reported speaking Tagalog at home, while 2.38% speak Spanish and 1.07% Tlingit.

There were 11,500 households out of which 37% had children under the age of 18 living with them, 51% were married couples living together, 11% had a female householder with no husband present, and 34% were non-families. 24% of all households were made up of individuals and 4% had someone living alone who was 65 years of age or older. The average household size was 2.6 and the average family size was 3.1.

In the borough, the population was spread out with 27% under the age of 18, 8% from 18 to 24, 33% from 25 to 44, 26% from 45 to 64, and 6% who were 65 years of age or older. The median age was 35 years. For every 100 females, there were 102 males. For every 100 females age 18 and over, there were 100 males.

The median income for a household in the borough was $62,000, and the median income for a family was $70,300. Males had a median income of $46,700 versus $33,200 for females. The per capita income for the borough was $26,700. 6% of the population and 4% of families were below the poverty line. 7% of those under the age of 18 and 4% of those 65 and older were living below the poverty line.