Lewisville (/ˈluːɪsvɪl/ LOO-iss-vil) is a city in the U.S. state of Texas, located in Denton County with portions extending into Dallas County. As one of the Mid-Cities within the Dallas–Fort Worth metroplex, the 2020 census reported a population of 111,822.

Originally called Holford's Prairie, Lewisville dates back to the early 1840s. The arrival of the town's first railroad in 1881 engendered its initial growth, and the expansion of the area's transportation infrastructure spurred further development in the early part of the 20th century. Lewisville incorporated in 1925, and when construction of Lewisville Lake was completed in the 1950s, the city began to expand rapidly.

Lewisville's proximity to Lewisville Lake has made it a recreational hub of the Dallas–Fort Worth metroplex. The area's transportation infrastructure has evolved around the I-35 Corridor along Interstate 35E. The diversity of its population and industry such as multiple landfills, has created a stable economic climate. Lewisville Independent School District provides most of the area's public education programs.

In 1841, the Republic of Texas chartered the Peters Colony Land Grant Company (named for William Smalling Peters, publisher of the song "Oh! Susanna") to settle the North Texas area. In 1844, John W. King and his wife settled on the east side of the prairie, where the city now lies. Baptist settlers from Platte County, Missouri, settled on the west side; among them were John and James Holford, who named the area Holford's Prairie. Further south, Presbyterians established a church and called it Flower Mound. In the confusion over land ownership after the Hedgcoxe War, Basdeal Lewis purchased Holford's Prairie in 1853 and renamed it after himself.

In 1845, the Fox family, which owned about a dozen slaves, buried a slave child called Melinda on the family farm, which eventually became the town's cemetery for black residents. Named Fox–Hembry Cemetery, the plot still exists today. After it had fallen into disrepair, local residents and businesses gathered to restore it in 2011. Though Abraham Lincoln was not on the ballot in the area for the 1860 Presidential election, residents of Lewisville (listed as "Hollforts" on election results) still gave John C. Breckinridge only a 44–31 majority over an electoral fusion option.

During Reconstruction, Lewisville became home to Denton County's first cotton gin. Built in 1867, it could produce up to three bales per day. The Thirteenth Texas Legislature chartered the Dallas and Wichita Railroad (later the Missouri–Kansas–Texas) on terms requiring 20 miles of track to be in running order by July 1, 1875. Lewisville paid the company $15,000 to come to the city, with a promise of another $5,000 on completion. The company fulfilled the deal by completing the railroad tracks to a point just south of Lewisville on the morning of the deadline, and the line began running full-time in 1881. Republicans in the Fourteenth Texas Legislature passed a law on April 30, 1874, prohibiting alcohol within two miles of the town. Many residents ignored the law, however, and the city retained as many as 17 saloons at one point. The population of the unincorporated town was 500 in 1888.

On January 15, 1925, residents voted by a margin of 17 votes to incorporate Lewisville, which established its official boundaries as a city. By 1930, Lewisville's population had increased to 853, making it the fourth-most populous municipality in Denton County (behind Denton, Sanger, and Pilot Point).

Because the city's economy had become diversified before the Wall Street Crash of 1929, Lewisville was relatively well insulated from the Great Depression. Many residents, including business leaders, nevertheless supported the New Deal programs of Franklin D. Roosevelt. By 1936, the Works Progress Administration operated a cannery in the city to provide temporary jobs for unemployed residents. As an extension of the Good Roads Movement, which had been prominent in Denton County since the early 1910s, residents formed the Good Roads Committee of Lewisville to lobby state and federal officials for funding to create better streets. Lewisville celebrated the paving of the U.S. Route 77 between Denton and Dallas in 1931 with a "Coming Out of the Mud" ceremony. The new pavement closed the "Lewisville Gap" between the two cities, a stretch of dirt road through the city that often became too muddy for travel.