Triangular trade, or triangle trade, is a historical term indicating (trade) among three ports or regions. Triangular trade usually evolves when a region has export commodities that are not required in the region from which its major imports come. Triangular trade thus provides a method for rectifying trade imbalances between the above regions.

The best-known triangular trading system is the transatlantic slave trade, that operated from the late 16th to early 19th centuries, carrying slaves, cash crops, and manufactured goods between West Africa, Caribbean or American colonies and the European colonial powers, with the northern colonies of British North America, especially New England, sometimes taking over the role of Europe. The use of African slaves was fundamental to growing colonial cash crops, which were exported to Europe. European goods, in turn, were used to purchase African slaves, which were then brought on the sea lane west from Africa to the Americas, the so called middle passage.

The Columbian Exchange was a dramatically widespread exchange of animals, plants, culture, human populations (including slaves), communicable disease, and ideas between the Western and Eastern Hemispheres. The contact between the two areas circulated a wide variety of new crops and livestock which supported increases in population in both hemispheres. Explorers returned to Europe with maize, potatoes, and tomatoes, which became very important crops in Eurasia by the 18th century. Similarly, Europeans introduced manioc and the peanut to tropical Southeast Asia and West Africa, where they flourished and supported growth in populations on soils that otherwise would not produce large yields.

In the biological and ecological exchange that took place following Spanish establishment of colonies in New World, people of Europe and Africa settled in the New World, and animals, plants and diseases of Eurasia and the Western Hemisphere were introduced to each area in an interchange.

This exchange of plants and animals transformed European, American, African, and Asian ways of life. New foods became staples of human diets, and new growing regions opened up for crops. For example, before AD 1000, potatoes were not grown outside of South America. By the 1840s, Ireland was so dependent on the potato that a diseased crop led to the devastating Irish Potato Famine. Since being introduced by 16th-century Portuguese traders, who brought them from the Americas,maize and manioc replaced traditional African crops as the continent’s most important staple food crops. New staple crops that were introduced to Asia from the Americas via Spanish colonizers in the 16th century, including maize and sweet potatoes, contributed to the population growth in Asia.