Wheaton is a city in and the county seat of DuPage County, Illinois, United States. It is located in Milton and Winfield Townships, approximately 25 miles (40 km) west of Chicago. As of the 2020 census, Wheaton's population was 53,970, making it the 27th-most populous municipality in the state.

The city dates its founding to the period between 1831 and 1837, following the Indian Removal Act, when Erastus Gary laid claim to 790 acres (320 ha) of land near present-day Warrenville. The Wheaton brothers arrived from Connecticut, and in 1837, Warren L. Wheaton laid claim to 640 acres (260 ha) of land in the center of town. Jesse Wheaton later made claim to 300 acres (120 ha) of land just west of Warren's. It was not long before other settlers from New England joined them in the community. In 1848, they gave the Galena and Chicago Union Railroad three miles (4.8 km) of right-of-way, upon which railroad officials named the depot Wheaton. In 1850, ten blocks of land were platted and anyone who was willing to build immediately was granted free land. In 1853, the lots were surveyed and a formal plat for the community was filed with the county. The community was then incorporated as a village on February 24, 1859, with Warren serving as its first President. The village was later incorporated as a city on April 24, 1890, when the first mayor of the city was selected, Judge Elbert Gary, son of Erastus Gary and founder of Gary, Indiana.

In 1857, the Illinois state legislature authorized an election to be held to decide the question of whether the DuPage county seat should remain in Naperville or be moved to the more centrally located Wheaton, which was on the Galena and Chicago Union Railroad. Naperville won the election by a vote of 1,542 to 762. Hostility between the two towns continued for the next decade and another election was held in 1867, in which Wheaton narrowly won by a vote of 1,686 to 1,635. At a cost of $20,000, the City of Wheaton quickly built a courthouse to house a courtroom, county offices, and a county jail. The building was dedicated on July 4, 1868.

However, animosity between the two towns continued, and in 1868, as records were moved from the old Naperville courthouse to the new courthouse in Wheaton, Naperville refused to turn over the remaining county records, prompting a band of Civil War veterans from Wheaton to conduct what came to be known as the "Midnight Raid" on the Naperville courthouse. As Wheatonites fled back on Wheaton-Naperville Road, Napervillians were able to secure some of the last remaining records, which were then taken to the Cook County Recorder in Chicago for safekeeping. During this time, Naperville was mounting a lawsuit against Wheaton accusing election judges of leaving their posts for lunch during the vote when duplicate ballot stuffing allegedly occurred. As the courts deliberated the fate of the county seat, the records were destroyed in the Great Chicago Fire of 1871. Shortly thereafter, Wheaton was officially proclaimed the county seat.

As demand for space increased, the courthouse was rebuilt in 1887 at a cost of $69,390, modeled after the courthouse in Aledo. This structure was used for the next 94 years until the county's rapid growth prompted the building of a brand new complex. The old courthouse is listed on the National Register of Historic Places, and was formerly used by National Louis University until National Louis moved to Lisle in 2004. It is currently being developed into luxury condominiums.

On November 2, 1990, the courthouse moved to a building about two miles (3.2 km) west in a new 57-acre (23 ha) complex at the corner of County Farm Road and Manchester Road. It was built at a cost of $52,500,000 and includes a 300,000-square-foot (30,000 m2) judicial building. In 1992, the county sued the architect and contractor for $4 million after several employees became ill from the ventilation system. In the end, however, the county received only $120,000 for minor repairs and the jury sided with the defendants, finding that the alleged problems were caused, primarily, by the county's negligent operation and maintenance of the ventilation system.

Wheaton has rapidly expanded since the 1950s, although population growth has slowed since the early 1990s, as the city has become increasingly landlocked. Downtown lost much business after the county courthouse facility moved two miles (3.2 km) west in 1990, but in the decade since, the downtown has seen a renaissance of sorts, with the creation of several significant condominium and business developments. One of the most recognizable landmarks of the city is Wheaton Center, a 758-unit apartment complex on 14 acres (5.7 ha) in downtown Wheaton. The six building complex includes two twenty-story high-rise buildings built in 1975.

In 1887, Wheaton prohibited the sale of alcoholic beverages, a ban which lasted until 1985 and applied to all supermarkets, convenience stores, restaurants, and other establishments.

According to the 2021 census gazetteer files, Wheaton has a total area of 11.49 square miles (29.76 km2), of which 11.32 square miles (29.32 km2) (or 98.55%) is land and 0.17 square miles (0.44 km2) (or 1.45%) is water.

As of the 2020 census, there were 53,970 people, 19,218 households, and 13,122 families residing in the city. The population density was 4,699.17 inhabitants per square mile (1,814.36/km2). There were 20,885 housing units at an average density of 1,818.46 units per square mile (702.11 units/km2). The racial makeup of the city was 79.01% White, 4.27% African American, 0.16% Native American, 7.50% Asian, 0.01% Pacific Islander, 2.24% from other races, and 6.81% from two or more races. Hispanic or Latino of any race were 6.49% of the population.

There were 19,218 households, out of which 31.2% had children under the age of 18 living with them, 58.66% were married couples living together, 6.35% had a female householder with no husband present, and 31.72% were non-families. 26.51% of all households were made up of individuals, and 10.01% had someone living alone who was 65 years of age or older. The average household size was 3.22 and the average family size was 2.61.

The city's age distribution consisted of 22.8% under the age of 18, 11.4% from 18 to 24, 24.7% from 25 to 44, 25.1% from 45 to 64, and 16.2% who were 65 years of age or older. The median age was 36.7 years. For every 100 females, there were 98.4 males. For every 100 females age 18 and over, there were 92.6 males.

The median income for a household in the city was $105,764, and the median income for a family was $129,579. Males had a median income of $73,771 versus $40,560 for females. The per capita income for the city was $51,688. About 3.3% of families and 5.7% of the population were below the poverty line, including 5.0% of those under age 18 and 7.3% of those age 65 or over.

In August 2010, the city was listed among the "Top 25 Highest Earning Towns" on CNN Money, citing a median family income of $113,517, and a median home price of $328,866, based on 2009 figures.

According to the City of Wheaton's 2022 Comprehensive Annual Financial Report, the top employers in the city were:

Wheaton boasts a vibrant downtown with many restaurants, shops and services. The Downtown Wheaton Association hosts many events throughout the year to promote local businesses, including The French Market, The Chili Cookoff, Vintage Rides, Boo-palooza (Downtown Wheaton Trick-or-Treat), A Dickens of a Christmas, Wheaton Wedding Walk and Wheaton's Wine & Cultural Arts Festival.

Downtown Wheaton is also home to perhaps one of the narrowest stores in the Chicago area. The Little Popcorn Store on Front Street was formerly an alley between two buildings, and features the exposed brick walls of its neighbors. The store has been around since the 1920s and sells candy for as little as 1¢ apiece, and fresh popcorn.

Other shopping districts in Wheaton include Danada Square West, and Danada Square East, named after Dan and Ada Rice, located on the north side of Illinois Route 56 (Butterfield Road), on the west and east side of Naperville Road. Just east of Danada Square East is Rice Lake Square, another open air shopping center. Just north of Danada Square East, along Naperville Road, is Town Square Wheaton, which was built in 1992, and is a mixed-use lifestyle center featuring clothing boutiques and restaurants. Other shopping areas include the Roosevelt Road and Geneva Road corridors.

Wheaton is home to the DuPage County Fairgrounds. Organized in 1954, the DuPage County Fair Association hosts the annual DuPage County Fair in late July. The fair annually attracts major entertainers, such as Ashlee Simpson, Plain White T's (2007), Travis Tritt, Jesse McCartney, Jars of Clay, Corbin Bleu (2008), The Academy Is..., The Original Wailers (2009), and Danny Gokey (2010).

Wheaton is also home to the historic Grand Theater, built in 1925. In recent years,[when?] the theater and volunteers undertook a restoration to its original state, complete with a lighted dome ceiling dotted with stars, and a newly painted floor. It celebrated its grand reopening on May 11, 2002, and on August 25, 2005, the theater was placed on the National Register of Historic Places. There was a sense of growing pessimism that the theater would ever be restored, due to lack of progress and funds. However, there was cause for hope when on January 23, 2010, when many cast members of the off-Broadway show Jersey Boys raised approximately $50,000 for restoration.

On July 10, 2010, the Grand Theater Corp. surrendered the deed to the building, to Suburban Bank and Trust Co, due in part to being delinquent on a $800,000 loan, carried by Suburban Bank and Trust Co.

On November 30, 2012, Jim Atten bought the building, intending to reopen it soon. Since then he has been repairing the property and leading the effort to remove temporary structures within the theater. He has worked closely with an architect and the city staff as the effort progresses. According to the Daily Herald newspaper, it will take an estimated $5 million to get the theater up and running again.

The Wheaton Public Library is frequently ranked as one of the top ten libraries in the nation compared to other libraries serving similarly sized populations. In 2006, a three-story addition was added, followed by significant renovations which were completed in 2007, to bring the square footage up from 74,000 to 124,000. The annual public library budget in 2018 was $4.084 million. As of 2019[update], the total circulation was 1,013,326, the number of items in the collection was 262,745, and the number of visitors was 525,711. The previous public library was converted into the DuPage County Historical Museum, between 1965 and 1967.

In May 2016, the library opened Café on the Park, a small restaurant located just inside the Wheaton Public Library's park-side (west) entrance.

In the United States House of Representatives, Wheaton is located both in Illinois's 3rd congressional district, which is held by Democrat Delia Ramirez, and Illinois's 6th congressional district, which is held by Democrat Sean Casten.

Wheaton College is located just east of downtown Wheaton. Sometimes referred to as "The Harvard of Evangelical schools", Wheaton College is known for being an interdenominational destination school for devout Christian students seeking an elite liberal arts education.

Wheaton's campus features the Billy Graham Center, named for the college's most famous alumnus, which contains a museum dedicated to both the history of American evangelism and the international ministry of Billy Graham. It features conceptual exhibits intended to convey Christian ideas. Wheaton College is also home to the Todd M. Beamer Student Center, which was dedicated on October 1, 2004, to the memory of Todd Beamer, a hero from United Airlines Flight 93, and two other Wheaton alumni who died in the September 11 attacks.

The Daniel F. and Ada L. Rice Campus of the Illinois Institute of Technology is also located in Wheaton, and is home to the School of Applied Technology and offers technology-oriented education and training for working professionals.

Several of the private schools in Wheaton are located near the town center; in addition, St. Francis High School is on the far west side of town. Wheaton Academy moved to West Chicago in 1945, and Wheaton Christian Grammar School moved to a new campus in Winfield in 2010, while still retaining its name.

Most of Wheaton is part of Community Unit School District 200. The Wheaton public school system is regularly listed among the finest in Illinois, with the School Board receiving the fifth consecutive Governance Award in 2020, from the Illinois Association of School Boards. A few families in the northeast corner of Wheaton reside in Glen Ellyn School District 41, and one elementary school that is located in the southeastern part of Wheaton, Briar Glen Elementary School, is part of Community Consolidated School District 89.

The Union Pacific West Line runs through downtown Wheaton and has been a staple of the city since its founding in the mid-1800s. Metra has two stops along the line in Wheaton, one at College Avenue serving Wheaton College, and another at West Street in the heart of the commercial district. It passes under a bridge just west of downtown, and over County Farm Road, just north of the DuPage County Government Complex.

Wheaton was also served by the Chicago Aurora and Elgin Railroad with passenger and freight service from 1902 to 1959. The CA&E right-of-way now constitutes the Illinois Prairie Path, one of the first rail trails. Carlton Avenue, UP Railroad, West Street, and Childs Street are the borders of the former site of the CA&E's headquarters and storage and maintenance facilities.

Pace provides bus service on multiple routes connecting Wheaton to Forest Park, Naperville, and other destinations.

Established in 1972 by the Wheaton Franciscan Sisters, Marianjoy Rehabilitation Hospital is a rehabilitation hospital located in a small unincorporated enclave on the west side of Wheaton on Roosevelt Road. It has been operated by Northwestern Medicine, since 2016. Marianjoy is a nonprofit hospital dedicated to the delivery of physical medicine and rehabilitation, with 127 beds.

Wheaton has forty-five churches located within city limits and an additional thirty places of worship in the outlying unincorporated areas, representing nearly forty religious denominations. The Genius Edition of Trivial Pursuit states that Wheaton has the "second most churches per capita in America."

Built in 1926, the national headquarters of the Theosophical Society in America is located on a 42-acre (17 ha) estate on the north side of Wheaton.

Wheaton is also the North American headquarters for the Institute of the Blessed Virgin Mary, which moved into its new home in June 1946.

On March 18, 2002, St. Michael Catholic Church in downtown Wheaton was destroyed by arson by a Wheaton resident and parishioner, Adam Palinski, now serving 39 years in prison. He lost his appeal, but still maintains his innocence. The church has since been rebuilt at a cost of $13 million, and reopened on March 18, 2006.