As of the census of 2000, there were 114,024 people, 45,693 households, and 21,704 families residing in the city. The population density was 4,221.1 people per square mile (1,629.9/km²). There were 47,218 housing units at an average density of 1,748.0 per square mile (675.0/km²), making it less dense than inner-ring Detroit suburbs like Oak Park and Ferndale (and than Detroit proper), but denser than outer-ring suburbs like Livonia. The racial makeup of the city was 74.68% White, 8.83% Black or African American, 0.29% Native American, 11.90% Asian, 0.04% Pacific Islander, 1.21% from other races, and 3.05% from two or more races. Hispanic or Latino of any race were 3.34% of the population. 14.9% were of German, 8.5% English and 7.9% Irish ancestry according to Census 2000. 80.6% spoke English, 3.2% Chinese or Mandarin, 3.1% Spanish, 1.9% Korean, 1.2% German, 1.1% Japanese and 1.0% French as their first language. Because of the pull of the university, the city has one of the highest foreign-born population percentages in the state sitting at 16.6%.

Out of the 45,693 households, 23.0% had children under the age of 18 living with them, 37.8% were married couples living together, 7.5% had a female householder with no husband present, and 52.5% were nonfamilies. 35.5% of households were made up of individuals and 6.6% had someone living alone who was 65 years of age or older. The average household size was 2.22 and the average family size was 2.90. The age distribution was 16.8% under 18, 26.8% from 18 to 24, 31.2% from 25 to 44, 17.3% from 45 to 64, and 7.9% were 65 or older. The median age was 28 years. For every 100 females there were 97.7 males; while for every 100 females age 18 and over, there were 96.4 males.

The median income for a household in the city was $46,299, and the median income for a family was $71,293 (these figures had risen to $51,232 and $82,293 respectively as of a 2007 estimate). Males had a median income of $48,880 versus $36,561 for females. The per capita income for the city was $26,419. About 4.6% of families and 16.6% of the population were below the poverty line, including 7.3% of those under age 18 and 5.1% of those age 65 or over.

Ann Arbor's crime rate was below the national average in 2000. The violent crime rate was further below the national average than the property crime rate; they were 48% and 11% less, respectively.