The Guianas, also spelled Guyanas or Guayanas, are a geographical region in north-eastern South America. Strictly, the term refers to the three Guianas: Guyana, Suriname, and French Guiana, formerly British, Dutch, and French Guiana respectively. Broadly, it refers to the South American coast from the mouth of the Orinoco to the mouth of the Amazon.

Politically it is divided into:

The three Guianas proper have a combined population of 1,718,651; Guyana: 804,567, Suriname: 612,985, and French Guiana: 301,099. Most of the population is along the coast. Due to the jungles to the south, the Guianas are one of the most sparsely populated regions on Earth.

Prior to c. 1815 there was a string of mostly Dutch settlements along the coast which changed hands several times. They were mostly several miles upriver to avoid the coastal marshes which were only drained later.

To the east and up the lower Amazon, there were a number of English, French and Dutch outposts that either failed or were expelled by the Portuguese. To the west, Spanish Guyana was thinly settled and interacted slightly with Pomeroon.

Before the arrival of European colonials, the Guianas were populated by scattered bands of native Arawak people. The native tribes of the Northern amazon forests are most closely related to the natives of the Caribbean; most evidence suggests that the Arawaks immigrated from the Orinoco and Essequibo River Basins in Venezuela and Guiana into the northern islands, and were then supplanted by more warlike tribes of Carib Indians, who departed from these same river valleys a few centuries later.

Over the centuries of the pre-colonial period, the ebb and flow of power between Arawak and Carib interests throughout the Caribbean resulted in a great deal of intermingling (some forced through capture, some accidental through contact). This ethnic mixing, particularly in the Caribbean margins like the Guianas, produced a hybridised culture. Despite their political rivalry, the ethnic and cultural blending between the two groups had reached such a level that, by the time the Europeans arrived, the Carib/Arawak complex in Guiana was so homogeneous that the two groups were almost indistinguishable to outsiders. Through the contact period following Columbus's arrival, the term "Guiana" was used to refer to all areas between the Orinoco, the Rio Negro, and the Amazon, and was seen so much as a unified, isolated entity that it was often referred to as the “Island of Guiana.”

Christopher Columbus first spotted the coast of the Guianas in 1498, but real interest in the exploration and colonisation of the Guianas, which came to be known as the "Wild Coast," did not begin until the end of the sixteenth century. In 1542, when Francisco de Orellana reached the mouth of the Amazon, he was pushed by winds and currents northwest along the Guiana coast until he reached a Spanish settlement west of Trinidad. Walter Raleigh began the exploration of the Guianas in earnest in 1594. He was in search of a great golden city at the headwaters of the Caroní River. A year later he explored what is now Guyana and eastern Venezuela in search of "Manoa", the legendary city of the king known as El Dorado. Raleigh described the city of El Dorado as being located on Lake Parime far up the Orinoco River in Guyana. Much of his exploration is documented in his books The Discoverie of the Large, Rich, and Bewtiful Empyre of Guiana, published first in 1596, and The Discovery of Guiana, and the Journal of the Second Voyage Thereto, published in 1606.