To improve the inadequate water distribution system, residents felt the need to incorporate the town.

On February 17, 1949, a petition signed by 42 eligible voters was presented to the Dallas County judge requesting an election for incorporation.

On March 3, 1949, the results were entered into the records of the Dallas County Commissioners Court, thereby creating the City of DeSoto.

During the 1970s, continued growth brought about improvements to the municipal infrastructure, including road construction, and a new water/sewage system.

On October 26, 1974, an election was held to determine the status of Woodland Hills, a small, incorporated community located northwest of DeSoto.

The rapid growth that began in the early 1970s was sustained throughout the 1980s; 1980 census figures put the city's population at slightly over 15,000.

Officials converted an abandoned strip center located at one of the city's main intersections into a unique central business district.

With roughly 45,500 residents as of 2005, DeSoto is the largest and most diverse city in southwest Dallas County.

On June 11, 2006, the National Civic League named DeSoto an "All-America City".

The All-America City Award is the nation's oldest community-recognition program and recognizes communities whose citizens work together to identify and tackle community-wide challenges and achieve uncommon results.

A 2015 article related a growing trend of largely middle class and educated African Americans moving to DeSoto.

[5] According to the United States Census Bureau, the city has a total area of 21.6 sq mi (56 km2), all land.