As of the census of 2000, there were 9,159 people, 3,501 households, and 2,562 families residing in the city. The population density was 1,167.5 people per square mile (450.5/km²). There were 3,714 housing units at an average density of 473.4/sq mi (182.7/km²). The racial makeup of the city was 96.09% White, 0.19% African American, 0.76% Native American, 0.55% Asian, 0.08% Pacific Islander, 0.94% from other races, and 1.40% from two or more races. Hispanic or Latino of any race were 2.43% of the population.
There were 3,501 households out of which 36.9% had children under the age of 18 living with them, 60.3% were married couples living together, 9.1% had a female householder with no husband present, and 26.8% were non-families. 21.6% of all households were made up of individuals and 9.5% had someone living alone who was 65 years of age or older. The average household size was 2.60 and the average family size was 3.04.
In the city the population was spread out with 27.6% under the age of 18, 7.4% from 18 to 24, 30.3% from 25 to 44, 21.2% from 45 to 64, and 13.5% who were 65 years of age or older. The median age was 35 years. For every 100 females there were 94.9 males. For every 100 females age 18 and over, there were 91.9 males.
The median income for a household in the city was $37,097, and the median income for a family was $40,875. Males had a median income of $35,339 versus $21,388 for females. The per capita income for the city was $16,387. About 5.8% of families and 9.2% of the population were below the poverty line, including 13.5% of those under age 18 and 4.5% of those age 65 or over.
Hayden is located on U.S. Route 95 at the junction of Route 41. It is also four miles north of Interstate 90 and Coeur D'Alene. The Coeur D'Alene airport is northwest of the city.