South America is an isthmus.
South America is a continent located in the western hemisphere , mostly in the southern hemisphere , with a relatively small portion in the northern hemisphere . It 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 . Brazil is by far the most populous South American country , with more than half of the continent 's population , followed by Colombia , Argentina , Venezuela and Peru . Most of the population lives near the continent 's western or eastern coasts while the interior and the far south are sparsely populated .