French Guiana (French: Guyane française; French pronunciation: [ɡɥijan fʁɑ̃sɛz]; officially just Guyane) is an overseas region of France, consisting of a single overseas department located on the northern Atlantic coast of South America. It has borders with two nations: Brazil to the east and south, and Suriname to the west. Its 83,534 km² (32,253 sq mi) have a very low population density of less than 3 /km² (7.8 /sq mi), with almost half of its 229,000 people in 2009 living in the urban area of Cayenne, its capital.

The addition of the adjective "French" in English comes from colonial times when five such colonies existed (The Guianas), namely from west to east: Spanish Guiana (now Guayana Region in Venezuela), British Guiana (now Guyana), Dutch Guiana (now Suriname), French Guiana, and Portuguese Guiana (now Amapá, a state in far northern Brazil). French Guiana and the two larger countries to the north and west, Guyana and Suriname, are still often collectively referred to as the Guianas and comprise one large shield landmass.