Founded in 1841 and formally incorporated as a city in February, 1856, the city's economy is primarily based on banking, commerce, telecommunications, computer technology, energy, and transportation, home to several Fortune 500 companies. Located in North Texas and a major city in the American South, Dallas is the core of the largest inland metropolitan area in the United States that lacks any navigable link to the sea. The city's prominence arose from its historical importance as a center for the oil and cotton industries, its position along numerous railroad lines, a strong industrial and financial sector, and its status as a major inland port (due largely to the presence of Dallas/Fort Worth International Airport, one of the largest and busiest in the world). It was rated as a beta world city by the Globalization and World Cities Study Group & Network.

Before Texas was claimed in the 18th century as a part of the Viceroyalty of New Spain by the Spanish Empire, the Dallas area was inhabited by the Caddo Native Americans. Later, France also claimed the area, but in 1819 the Adams-Onís Treaty made the Red River the northern boundary of New Spain, officially placing the future location of Dallas well within Spanish territory. The area remained under Spanish rule until 1821, when Mexico declared independence from Spain and the area became part of the Mexican state of Coahuila y Tejas. In 1836, the Republic of Texas broke off from Mexico to become an independent nation. In 1839, four years into the Republic's existence, Warren Angus Ferris surveyed the area around present-day Dallas. Two years later, John Neely Bryan established a permanent settlement near a river he found and called that settlement Dallas. The Republic of Texas was then annexed by the United States in 1845 and Dallas County was established the following year. It is uncertain whether the city was named after George Mifflin Dallas, the U.S. Vice President under James Knox Polk.

Dallas is the county seat of Dallas County. Portions of the city extend into neighboring Collin, Denton, Kaufman, and Rockwall counties. According to the United States Census Bureau, the city has a total area of 385 square miles (997.1 km2), 342.5 square miles (887.1 km2) of it being land and 42.5 square miles (110.1 km2) of it (11.03%) water. Dallas makes up one-fifth of the much larger urbanized area known as the Dallas–Fort Worth Metroplex, in which one quarter of all Texans live.

Many people are coming to live in Dallas Texas and the surrounding Metroplex, because of its diverseness, and its Robust Economy. It continues to grow rapidly. There are many jobs in the D/FW area. and Housing is extremely low compared to the Coastal States.

Note: It is also located on the 33rd parallel.

Dallas and its surrounding area are mostly flat; the city itself lies at elevations ranging from 450 feet (137 m) to 550 feet (168 m). The western edge of the Austin Chalk Formation, a limestone escarpment (also known as the "White Rock Escarpment"), rises 200 feet (61 m) and runs roughly north-south through Dallas County. South of the Trinity River, the uplift is particularly noticeable in the neighborhoods of Oak Cliff and the adjacent cities of Cockrell Hill, Cedar Hill, Grand Prairie, and Irving. Marked variations in terrain are also found in cities immediately to the west in Tarrant County surrounding Fort Worth, as well as along Turtle Creek north of Downtown.

Dallas, like many other cities in the world, was founded along a river. The city was founded at the location of a "white rock crossing" of the Trinity River, where it was easier for wagons to cross the river in the days before ferries or bridges. The Trinity River, though not usefully navigable, is the major waterway through the city. Its path through Dallas is paralleled by Interstate 35E along the Stemmons Corridor, then south alongside the western portion of Downtown and past south Dallas and Pleasant Grove, where the river is paralleled by Interstate 45 until it exits the city and heads southeast towards Houston. The river is flanked on both sides by 50 feet (15 m) tall earthen levees to protect the city from frequent floods. Since it was rerouted in 1908, the river has been little more than a drainage ditch within a floodplain for several miles above and below downtown Dallas, with a more normal course further upstream and downstream, but as Dallas began shifting towards postindustrial society, public outcry about the lack of aesthetic and recreational use of the river ultimately gave way to the Trinity River Project, which was initialized in the early 2000s and is scheduled to be completed in the 2010s. If the project materializes fully, it promises improvements to the riverfront in the form of man-made lakes, new park facilities and trails, and transportation upgrades.

The project area will reach for over 20 miles (32 km) in length within the city, while the overall geographical land area addressed by the Land Use Plan is approximately 44,000 acres (180 km2) in size—about 20% of the land area in Dallas. Green space along the river will encompass approximately 10,000 acres (40 km2), making it one of the largest and diverse urban parks in the world.

White Rock Lake, a reservoir constructed at the beginning of the 20th century, is Dallas' other significant water feature. The lake and surrounding park are a popular destination among boaters, rowers, joggers, and bikers, as well as visitors seeking peaceful respite from the city at the 66-acre (267,000 m2) Dallas Arboretum and Botanical Garden, located on the lake's eastern shore. White Rock Creek feeds into White Rock Lake, and then exits on to the Trinity River southeast of downtown Dallas. Trails along White Rock Creek are part of the extensive Dallas County Trails System. Bachman Lake, just northwest of Love Field Airport, is a smaller lake also popularly used for recreation. Northeast of the city is Lake Ray Hubbard, a vast 22,745-acre (92 km2) reservoir located in an extension of Dallas surrounded by the suburbs of Garland, Rowlett, Rockwall, and Sunnyvale. To the west of the city is Mountain Creek Lake, once home to the Naval Air Station Dallas (Hensley Field) and a number of defense aircraft manufacturers. North Lake, a small body of water in an extension of the city limits surrounded by Irving and Coppell, initially served as a water source for a nearby power plant but is now being targeted for redevelopment as a recreational lake due to its proximity to Dallas-Fort Worth International Airport, a plan that the lake's neighboring cities oppose.

Dallas has a humid subtropical climate, though it is located in a region that also tends to receive warm, dry winds from the north and west in the summer, bringing temperatures well over 100 °F (38 °C) at times and heat-humidity indexes soaring to as high as 117 °F (47 °C). When only temperature itself is accounted for, the north central Texas region where Dallas is located is one of the hottest in the United States during the summer months, usually trailing only the Mojave Desert basin of Arizona, southern Nevada, and southeastern California.