This area was designated as within Royal Oak Township; it was first settled by European Americans in 1840, but remained sparsely populated for many decades following. The first major housing development was constructed in 1914 at the time of World War I, when the township sold land to the Majestic Land Company to be developed as the Oak Park subdivision. The subdivision was incorporated as a village on May 3, 1927. Two petition drives during the Great Depression to dissolve the village government and return it to the township, citing "excessively high cost of village government," failed in 1931 and 1933. The village incorporated as a city on October 29, 1945, following the end of World War II.

Stimulated by the GI Bill which aided veterans in buying new housing, highways to improve commuting, and planned developments in the late 1950s, Oak Park from 1950 to 1960 was named as "America's Fastest Growing City". Its population increased sevenfold, from 5,000 to more than 36,000. Much of its population was second- and third-generation children of European immigrants who had settled in Detroit in the early 20th century. These included many Jewish Americans, many of whom are of the Orthodox faith. Major civic improvements in this period included construction of an outdoor swimming pool and an ice rink in Major Park (now known as Shepherd Park, after former mayor David Shepherd, but long known informally as Oak Park Park).

In 1995, Detroit-based window manufacturer WeatherGard moved its headquarters to Oak Park.

In 2002 and 2004, the city annexed portions of neighboring Royal Oak Township to expand its land and tax base.

On November 8, 2011, the citizens of Oak Park elected a new mayor, Marian McClellan. She was the city's first new mayor in 22 years, replacing the long-serving Jerry Naftaly.

In April 2015, the city approved the development of a new FedEx distribution center which will be located on a 60-acre plot of land at the site of the former Detroit Artillery Armory. The facility opened on March 31, 2017.

On May 5, 2015, the citizens of Oak Park voted to allow mixed drinks to be sold at businesses within city limits, in addition to beer and wine, which were previously allowed.

On November 3, 2015, the citizens of Oak Park re-elected McClellan, who was running against Aaron Tobin.

According to the United States Census Bureau, the city has a total area of 5.16 square miles (13.36 km), all of it land.

Oak Park is adjacent to the cities of Detroit to the south, Southfield to the west, Pleasant Ridge, Ferndale, and Royal Oak Township to the east, Huntington Woods to the northeast, and Berkley to the north.

Oak Park is bordered to the south by 8 Mile Road (M-102), to the north by 11 Mile Road, to the Northeast by Coolidge Highway and 10 Mile Road/I-696, to the west by Greenfield Road, to the east by Sherman Street and Forest Street, and to the southeast by 9 Mile Road, Republic Street, Northend Avenue, and Meyers Avenue.

• I-696 (Walter P. Reuther Freeway) passes through the northernmost part of the city and forms its northern border with Huntington Woods. The Detroit Zoo is located on the opposite side of the freeway in Huntington Woods and Royal Oak.
• M-102 (8 Mile Road) is the Oakland-Wayne county line and forms Oak Park's entire southernmost border with the city of Detroit.
• M-10 (John C. Lodge Freeway) is a major thoroughfare near the city.

As of the census of 2010, there were 29,319 people, 11,719 households, and 7,533 families residing in the city. The population density was 5,682.0 inhabitants per square mile (2,193.8/km). There were 12,782 housing units at an average density of 2,477.1 units per square mile (956.4 units/km). The racial makeup of the city was 57.4% African American, 37.4% White, 1.4% Asian, 0.2% Native American, 0.5% from other races, and 3.0% from two or more races. Hispanic or Latino people of any race were 1.4% of the population.

There were 11,719 households, of which 35.7% were non-families, 35.4% were married couples living together, 33.3% had children under the age of 18 living with them, 23.9% had a female householder with no husband present, and 5.1% had a male householder with no wife present. 30.9% of all households were made up of individuals, and 11% had someone living alone who was 65 years of age or older. The average household size was 2.50 and the average family size was 3.16.

The median age in the city was 37.5 years. 24.9% of residents were under the age of 18; 9.6% were between the ages of 18 and 24; 25.7% were from 25 to 44; 26.9% were from 45 to 64; and 12.9% were 65 years of age or older. The gender makeup of the city was 45.1% male and 54.9% female.

As of the census of 2000, there were 29,793 people, 11,104 households, and 7,595 families residing in the city. The population density was 2,291.5 people/km (5,935 people/sq mi). There were 11,370 housing units at an average density of 874.5 units/km (2,265 units/sq mi). The racial makeup of the city was 46.95% White, 45.95% African American, 2.18% Asian, 0.17% Native American, 0.02% Pacific Islander, 0.60% from other races, and 4.13% from two or more races. 1.28% of the population were Hispanic or Latino of any race.

There were 11,104 households, out of which 44.0% were married couples living together, 34.4% had children under the age of 18 living with them, 31.6% were non-families, and 19.5% had a female householder with no husband present. 26.6% of all households were made up of individuals, and 10.4% had someone living alone who was 65 years of age or older. The average household size was 2.68 and the average family size was 3.29.

In the city, the population was spread out, with 28.2% under the age of 18, 8.0% from 18 to 24, 29.8% from 25 to 44, 21.8% from 45 to 64, and 12.2% who were 65 years of age or older. The median age was 35 years. For every 100 females, there were 88.0 males. For every 100 females age 18 and over, there were 81.9 males.

The median income for a household in the city was $48,697, and the median income for a family was $54,786. Males had a median income of $40,922 versus $35,968 for females. The per capita income for the city was $21,677. 9.4% of the population and 7.8% of families were below the poverty line. Out of the total population, 10.9% of those under the age of 18 and 13.9% of those 65 and older were living below the poverty line.

Oak Park's educational history began with the Clinton School, a one-room schoolhouse on property donated by Barney Clinton in the early 20th century. As the population grew rapidly, Clinton School was expanded and more elementary schools were built, particularly beginning in the 1950s.

Clinton School was made a junior high school and another was built in the mid-1960s, then named for the poet Robert Frost. At that time, one school in Oak Park had a special education department for children with learning disabilities: Lessenger Elementary School on Albany St. at Sunset St. Consequently, many families with such special children gravitated to the neighborhood surrounding Lessenger, creating a "cluster" of such families rarely found elsewhere.

Educational achievement was the long consistent pattern in Oak Park. Over 85% of Oak Park High School graduates continued their education immediately after high school, whether in college, or in trade or vocational schools. In the 1950s and 1960s the school system was renowned statewide due to the efforts of progressive and dedicated teachers and community support which liberally allocated tax dollars to fund education through voter approved bond issues.

The high school had an average score of 3.8 on the state's MEAP test in 2011. This was one of the lowest scores in Oakland County.

Students residing between 10 Mile Rd. and 11 Mile Rd. are in the Berkley School District. A square mile on the east end of Oak Park is in the neighboring Ferndale Public Schools; the majority of the city is in Oak Park Schools.