According to the Census Bureau's Population Estimates Program (PEP), the population of Santa Cruz County on on July 1, 2006 was 249,705. This is a 2.3% drop from the recorded number of people on April 1, 2000; the PEP builds this estimate from such year-by-year information as births, deaths, domestic and international immigration.
As of the census of 2000, there were 255,602 people, 91,139 households, and 57,144 families residing in the county. The population density was 574 people per square mile (222/km²). There were 98,873 housing units at an average density of 222 per square mile (86/km²). The racial makeup of the county was 75.09% White, 0.97% Black or African American, 0.96% Native American, 3.44% Asian, 0.15% Pacific Islander, 15.02% from other races, and 4.37% from two or more races. 26.79% of the population were Hispanic or Latino of any race. 10.0% were of German, 8.9% English, 8.2% Irish and 6.3% Italian ancestry according to Census 2000. 72.5% spoke English and 22.3%Spanish as their first language. 2.3% (approximately 6,000) register as Jewish, placing Santa Cruz County as the 91st highest percentage of Jews in the United States (see American Jews).
There were 91,139 households out of which 31.90% had children under the age of 18 living with them, 48.00% were married couples living together, 10.20% had a female householder with no husband present, and 37.30% were non-families. 25.10% of all households were made up of individuals and 8.20% had someone living alone who was 65 years of age or older. The average household size was 2.71 and the average family size was 3.25.
In the county the population was spread out with 23.80% under the age of 18, 11.90% from 18 to 24, 30.80% from 25 to 44, 23.50% from 45 to 64, and 10.00% who were 65 years of age or older. The median age was 35 years. For every 100 females there were 99.70 males. For every 100 females age 18 and over, there were 97.80 males.
The median income for a household in the county was $53,998, and the median income for a family was $61,941. Males had a median income of $46,291 versus $33,514 for females. The per capita income for the county was $26,396. About 6.70% of families and 11.90% of the population were below the poverty line, including 12.50% of those under age 18 and 6.30% of those age 65 or over.
Santa Cruz county residents tend to be well-educated. 38.3% of residents age 25 and older hold a bachelor's degree at least, significantly higher than the national average of 27.2% and the state average of 29.5%.
Santa Cruz County is served by the Santa Cruz Metropolitan Transit District bus system. A "Highway 17 Express" bus between Santa Cruz and San Jose is jointly operated by the SCMTD and the Santa Clara Valley Transportation Authority. Greyhound Lines bus service also serves Santa Cruz County.