Metro Detroit's suburbs are among the most affluent in the nation. Oakland County is the fourth wealthiest county in the United States among counties with more than one million people. The county's automotive-oriented economic base, coined "Automation Alley," is one of the largest employment centers for engineering and related occupations in the United States. Oakland County has shared in the recent economic hardships brought on by troubles at General Motors, Ford, and Chrysler, although it has fared better than Detroit and Flint, as its economy is more diverse and less reliant on manufacturing jobs. All three automotive companies are major employers within southeast Michigan and have significant investments within Oakland County.
As of the census of 2000, there were 1,194,156 people, 471,115 households, and 315,175 families residing in the county. The population density was 1,369 people per square mile (528/km²). There were 492,006 housing units at an average density of 564 per square mile (218/km²). The racial makeup of the county was 82.75% White, 10.11% Black or African American, 0.27% Native American, 4.14% Asian American, 0.02% Pacific Islander, 0.84% from other races, and 1.86% from two or more races. 2.43% of the population were Hispanic or Latino of any race. Regarding ancestry, 14.4% were German, 9.0% Irish, 8.5% English, 8.5% Polish, 5.7% Italian and 5.5% American, according to Census 2000. 87.4% spoke English, 2.0% Spanish, 1.3% Syriac and 1.0% Arabic as their first language.
The 2000 census showed two Native American tribes with more than 1,000 members in Oakland County. There were 2,095 Cherokee and 1,458 Chippewa.
There were 471,115 households, of which 32.40% had children under the age of 18 living with them. 54.20% were married couples living together, 9.50% had a female householder with no husband present, and 33.10% were non-families. 27.30% of all households were made up of individuals and 8.50% had someone living alone who was 65 years of age or older. The average household size was 2.51 and the average family size was 3.09.
Among Asian-Americans, eight ethnic groups had more than 1,000 members in the county. The most numerous were those of Asian Indian decent, with 20,705. Next were those of Chinese heritage, numbering 10,018. Next were those of Japanese (5,589), Filipino (5,450) Korean (5,351), Vietnamese (1,687), Pakistani (1,458) and Hmong (1,210) ancestry.
The county's population was spread out in terms of age, with 25.20% of people under the age of 18, 7.20% from 18 to 24, 32.40% from 25 to 44, 23.90% from 45 to 64, and 11.30% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 95.90 males. For every 100 females age 18 and over, there were 92.70 males.
The median income for a household in the county was $61,907, and the median income for a family was $75,540 (these figures had risen to $67,619 and $85,468 respectively as of a 2007 estimate). Males had a median income of $55,833 versus $35,890 for females. The per capita income for the county was $32,534. About 3.80% of families and 5.50% of the population were below the poverty line, including 6.50% of those under age 18 and 6.50% of those age 65 or over.
In 2005, the U.S. Census Bureau estimated that non-Hispanic whites (including Arabs and Chaldeans) formed 78.6% of the population; African-Americans, 11.8%; Asian-Americans, 5.3%; and Hispanic or Latino people (of any race), 2.8%.