As of the census of 2000, there were 788,149 people, 309,203 households, and 210,876 families residing in the county. The population density was 1,640 people per square mile (633/km²). There were 320,276 housing units at an average density of 667 per square mile (257/km²). The racial makeup of the county was 92.66% White, 2.71% Black or African American, 0.31% Native American, 2.14% Asian, 0.02% Pacific Islander, 0.39% from other races, and 1.77% from two or more races. 1.58% of the population were Hispanic or Latino of any race. 18.1% were of German, 17.1% Polish, 13.6% Italian, 7.5% Irish and 5.5% English ancestry according to Census 2000. 87.6% spoke English, 1.7% Italian, 1.4% Polish, 1.2% Spanish, 1.1% Arabic and 1.1% Syriac as their first language.
Two Native American tribes had over 1000 people who self-identified with the tribe in Macomb County in 2000. 1781 county residents indicated that they were Cherokee on the census form. 1038 did the same for being Chippewa. This is the tribe known as the Ojibwa. It should be kept in mind that whether someone marked "Ojibwa", "Chippewa" or "Anishabaag" it was all grouped together in the reported counts.
Among Asians groups, Macomb County has six with over 1000 people. The most numerous were the 5713 Asian Indians. Filipinos came in a close second numbering 4155, this includes many children who are Filipino on their mother's side and European-American on their father's side. Chinese number 2489. Koreans numbered 1853, while Vietnamese numbered 1557. There were 1103, the only Asian group without a nation to be so recognized. It should be remembered that people from Iran and further west are classed as whites.
There were 309,203 households out of which 31.10% had children under the age of 18 living with them, 54.30% were married couples living together, 10.10% had a female householder with no husband present, and 31.80% were non-families. 26.90% of all households were made up of individuals and 10.30% had someone living alone who was 65 years of age or older. The average household size was 2.52 and the average family size was 3.09.
In the county the population was spread out with 24.10% under the age of 18, 8.00% from 18 to 24, 31.50% from 25 to 44, 22.80% from 45 to 64, and 13.70% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 96.00 males. For every 100 females age 18 and over, there were 92.90 males.
The median income for a household in the county was $52,102, and the median income for a family was $62,816. Males had a median income of $48,303 versus $30,215 for females. The per capita income for the county was $24,446. About 4.00% of families and 5.60% of the population were below the poverty line, including 7.00% of those under age 18 and 6.40% of those age 65 or over.
The years 2000-2005 saw the African American population in Macomb County more than double. This growth largely resulted from an exodus of African Americans from Detroit. By 2005 Census estimates for Macomb County showed it was 5.6% African American, meaning that the growth of the African-American population in the county had been well over 100% in the last 5 years. The percentage of Asians had risen to 2.9%, largely fueled by the exodus of the eastside Detroit Hmong population northward into Warren. The American Community Survey showed 1.5% of Macomb County's population reporting two or more races.
According to the 2006 American Community Survey the average family size is 3.15. The population of 25 and over is 571,463. 86.9% of that population has graduated from High school, 21% of that population has a Bachelor's degree or higher. About 14.3 of that population is disabled. 12.5% of Macomb's population can speak another language at home.