South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern subregion of the Americas.

South America is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest.

The continent includes twelve sovereign states: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela; two dependent territories: the Falkland Islands and South Georgia and the South Sandwich Islands; and one internal territory: French Guiana.

The territories of the ABC islands of the Kingdom of the Netherlands (north of Venezuela in the Western Caribbean), the British Overseas Territory of Saint Helena, Ascension and Tristan da Cunha (in the Southern Atlantic), Bouvet Island (a dependency of Norway), Panama, and the island Republic of Trinidad and Tobago may also be considered parts of South America.

South America has an area of 17,840,000 square kilometers (6,890,000 sq mi). Its population as of 2021 has been estimated at more than 434 million. South America ranks fourth in area (after Asia, Africa, and North America) and fifth in population (after Asia, Africa, Europe, and North America). Brazil is by far the most populous South American country, with almost half of the continent's population, followed by Colombia, Argentina, Venezuela and Peru. In recent decades, Brazil has also generated half of the continent's GDP and has become the continent's first regional power.

Most of the population lives near the continent's western or eastern coasts while the interior and the far south are sparsely populated. The geography of western South America is dominated by the Andes mountains; in contrast, the eastern part contains both highland regions and vast lowlands where rivers such as the Amazon, Orinoco and Paraná flow. Most of the continent lies in the tropics, except for a large part of the Southern Cone located in the middle latitudes.

The continent's cultural and ethnic outlook has its origin with the interaction of Indigenous peoples with European conquerors and immigrants and, more locally, with African slaves. Given a long history of colonialism, the overwhelming majority of South Americans speak Spanish or Portuguese, and societies and states are rich in Western traditions. Relative to Europe, Asia and Africa, post-1900 South America has been a peaceful continent with few wars, although high rates of violent crime remain a concern in some countries.