Las Vegas (often abbreviated as Vegas) is the most populous city in the state of Nevada, United States, the seat of Clark County, and an internationally known vacation, shopping, entertainment, and gambling destination. It was established in 1905 and officially became a city in 1911. With the growth that followed, Vegas became the largest U.S. city founded in the 20th century.

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 4½ mi (7.2 km) stretch of Las Vegas Boulevard is mostly outside the Las Vegas city limits, in the unincorporated towns of Paradise and Winchester.

The center of gambling in the United States, Las Vegas is marketed as The Entertainment Capital of the World and is famous for its massive, lavish casino resorts. It is also commonly known as Sin City.