Las Vegas is the most populous city in the state of Nevada, the seat of Clark County, and an internationally renowned major resort city for gambling, shopping, and entertainment. Although established in 1905, Las Vegas officially became a city in 1911. With the growth that followed, Las Vegas became the most populous American city founded in the 20th century, preceding the 19th century founding of Chicago. As the 28th most populous city in the United States, Las Vegas is one of the most populous cities in the American West.

The name Las Vegas is often applied to the unincorporated areas of Clark County that surround the city, especially the resort areas on and near the Las Vegas Strip. This 4.5-mile (7.2-km) stretch of Las Vegas Boulevard is mostly outside the city limits, in the unincorporated towns of Paradise and Winchester.

Las Vegas, billed as The Entertainment Capital of the World, is famous for massive and lavish casino resorts, the unrestricted availability of alcoholic beverages (as is true throughout Nevada), and adult entertainment. Once officially referred to as Sin City, this image made Las Vegas a popular setting for films and television programs.