Before European settlement, the land that now makes up Aurora was the territory of the Arapaho, Cheyenne, Núu-agha-tʉvʉ-pʉ̱ (Ute), and Očeti Šakówiŋ (Sioux) tribes. Aurora originated in the 1880s as the town of Fletcher, taking its name from Denver businessman Donald Fletcher who saw it as a real estate opportunity. He and his partners staked out four square miles (10 km²) east of Denver, but the town - and Colorado - struggled mightily after the Silver Crash of 1893. At that point Fletcher skipped town, leaving the community with a huge water debt. Inhabitants decided to rename the town Aurora in 1907, after one of the subdivisions composing the town, and Aurora slowly began to grow in Denver's shadow becoming the fastest-growing city in the United States during the late 1970s and early 1980s. Aurora, composed of hundreds of subdivisions, thus carries the name of one of the original development plats from which it sprang.

Aurora's growing population in recent decades has led to efforts for co-equal recognition with its larger neighbor.^{[citation needed]} Former mayor Dennis Champine once expressed the somewhat whimsical notion that eventually the area would be called the "Aurora/Denver Metropolitan Area". Indeed, since the 2000 Census Aurora has surpassed Denver in land area, and much of Aurora is undeveloped, while Denver is more fully built-out. However, such efforts are somewhat hampered by the lack of a large, historically important central business district in the city. Aurora is largely suburban in character, as evidenced by the city's modest number of multi-story buildings.

A large military presence has existed in Aurora since the early 20th century. In 1918, Army General Hospital #21 (later renamed Fitzsimons Army Hospital) opened, with the U.S. government expanding and upgrading the hospital facilities in 1941 just in time to care for the wounded servicemen of World War II. Lowry Air Force Base was opened in 1938, straddling the border of Aurora and Denver. It eventually closed in 1994, and has been redeveloped into a master-planned community featuring residential, commercial, business and educational facilities. In 1942, the Army Air Corps built Buckley Field, which has been renamed Naval Air Station, Buckley Air National Guard Base and finally Buckley Air Force Base. The base, home of the 460th Space Wing and the 140th Wing Colorado Air National Guard, is Aurora's largest employer.

President Warren G. Harding visited Fitzsimons Army Hospital in 1923, and President Franklin D. Roosevelt visited in 1936. In 1943 the hospital was the birthplace of 2004 Democratic presidential candidate John Kerry. President Dwight D. Eisenhower recovered from a heart attack at Fitzsimons for seven weeks during the fall of 1955. Decommissioned in 1999, the facility is part of the Anschutz Medical Campus of the University of Colorado Denver, and the Fitzsimons Life Science District. The Anschutz Medical Campus also includes the University of Colorado Hospital, which moved to Aurora from Denver in 2007, and the Children's Hospital. The first carbon-ion radiotherapy research and treatment facility in the U.S. has been proposed at the site. These facilities will employ a workforce of 32,000 at build-out.

In 1965, mayor Norma O. Walker became the first woman to head a U.S. city with a population over 60,000.

In 1978, the cult coming-of-age film Over the Edge was filmed in Aurora; the crime drama has been named the “signature film” of Denver.

In 1979, it was announced that a science fiction theme park would be built in Aurora using the sets of a $50 million film based on the fantasy novel Lord of Light. However, due to legal problems the project was never completed. The script of the unmade film project, renamed Argo, was used as cover for the "Canadian Caper": the exfiltration of six U.S. diplomatic staff trapped by the Iranian hostage crisis.

In 1993, Cherry Creek State Park on the southwestern edge of Aurora was the location for the papal mass of the 8th World Youth Day with Pope John Paul II, attended by an estimated 500,000 people.

Aurora is split among three counties and lies distant from the respective county seats. A consolidated city and county government such as those found elsewhere in Colorado (Denver and Broomfield) was considered in the mid-1990s but failed to win approval by city voters; the issue was reconsidered in 2006.

Aurora Sports Park opened in 2003. In 2004, Aurora was honored as the Sports Illustrated magazine's 50th Anniversary "Sportstown" for Colorado because of its exemplary involvement in facilitating and enhancing sports. The city attracts more than 30 regional and national sports tournaments annually to Aurora's fields, which include the 220-acre (0.89 km²) Aurora's active populace is also reflected in the variety of professional athletes hailing from the city. Aurora's first semi-professional sports franchise, the Aurora Cavalry in the International Basketball League, began play in 2006 but folded by season's end due to budget mishaps.^{[citation needed]}

In 2008, Aurora was designated an All-America City by the National Civic League.

In 2017, the Republic of El Salvador opened a consulate in Aurora, serving Colorado, Kansas, Nebraska, and Wyoming.

On July 20, 2012, Aurora was the site of the third largest mass shooting in terms of number of casualties in United States history at the time (now the eighteenth largest) and the second-deadliest shooting in Colorado after the 1999 Columbine High School massacre. The shooting occurred just after midnight, when James Eagan Holmes opened fire during the midnight premiere of The Dark Knight Rises in a Century movie theater, killing 12 people and injuring 70 others. Holmes was arrested and was eventually sentenced to 12 life sentences in prison with an additional required 3,318 years. The shooting drew an international response from world leaders. U.S. President Barack Obama visited victims, as well as local and state officials, and addressed the nation in a televised address from Aurora on July 22. Actor Christian Bale, who plays Batman in the film, also visited some victims in hospitals. The events marked a turning point in recognition and public perception of the city; rather than referring to the site as being in "Denver" or "suburban Denver", as would have been typical before the event, virtually all media accounts of the incident unequivocally named "Aurora" as its location.

As of the 2010 census, there were 325,078 people, 121,191 households, and 73,036 families residing in the city. The population density was 1,939.6 inhabitants per square mile (748.9/km²). There were 131,040 housing units at an average density of 766.7 per square mile (296.0/km²). The racial makeup of the city was 61.1% White, 15.7% African American, 4.9% Asian (1.1% Korean, 0.8% Vietnamese, 0.5% Filipino, 0.5% Chinese, 0.5% Indian, 0.2% Japanese, 0.1% Thai, 0.1% Cambodian, 0.1% Burmese, 0.1% Nepalese, 0.1% Pakistani, 0.1% Indonesian), 1.0% Native American, 0.3% Pacific Islander, 11.6% from other races, and 5.2% from two or more races. Hispanic or Latino of any race were 28.7% of the population; 21.9% of Aurora's population is of Mexican heritage, 1.0% Salvadoran, 0.7% Puerto Rican, 0.4% Guatemalan, 0.3% Honduran, 0.3% Peruvian, 0.2% Cuban, 0.2% Colombian and 0.1% Nicaraguan.Non-Hispanic Whites were 47.3% of the population in 2010, compared to 85.1% in 1980.

Aurora is a center of Colorado's refugee population. There are about 30,000 Ethiopians and Eritreans living in the Denver-Aurora area. There is also a sizable population of Nepalese refugees.

There were 121,191 households, out of which 35.5% had children under the age of 18 living with them, 46.9% were married couples living together, 13.1% had a female householder with no husband present, and 34.8% were non-families. 27.4% of all households were made up of individuals, and 5.7% had someone living alone who was 65 years of age or older. The average household size was 2.6 and the average family size was 3.2.

In the city, the population was spread out, with 27.3% under the age of 18, 6.8% from 18 to 24, 37.6% from 25 to 44, 16.8% from 45 to 64, and 8.9% who were 65 years of age or older. The median age was 32 years. For every 100 females, there were 100.5 males. For every 100 females age 18 and over, there were 95.8 males.

The median income for a household in the city was $46,507, and the median income for a family was $52,551. Males had a median income of $35,963 versus $30,080 for females. The per capita income for the city was $21,095. About 6.8% of families and 8.9% of the population were below the poverty line, including 12.0% of those under age 18 and 6.1% of those age 65 or over.

Some notable individuals who were born in or have lived in Aurora include: