The sound was named by John Strong in 1690 for Viscount Falkland, the name only later being applied to the archipelago and its two largest islands. The Spanish name "Estrecho de San Carlos" refers to the ship San Carlos which visited in 1768; confusingly the English name "San Carlos Water" is a much smaller inlet on East Falkland - and gives its name to San Carlos, Port San Carlos and the San Carlos River.
Islands in the Falkland Sound include Narrows Island, Great Island, the Tyssen Islands and the Swan Islands. Eddystone Rock is at the northern end of the Sound; the Arch Islands are at the southern end.
Inlets and bays on the Sound include: Fox Bay, Port Howard (West Falkland); Grantham Sound, San Carlos Water, Ruggles Bay (East Falkland)
About 400 million years ago part of Gondwana, which broke from what is now Africa and drifted westwards relative to Africa. During the mid-Jurassic period (about 170 million years ago) the land fragment that was to become East Falklands and the land fragment that was to become West Falklands rotated about 120° relative to each other. As a result, the fold lines in West Falkland run almost north-west to south-east, parallel to the Sound.
Those in the northern part of East Falkland run east-west, forming the eastern part of northern entrance to the Sound and bordering on the northern banks of San Carlos Water. The boundary between these two land fragments, the Falkland Sound Fault, lies close to and parallel with the western shore of the Sound. Lafonia, which is a much newer formation, has no folds.
- Otley H, Munro G, Clausen A and Ingham B. (2008). "Falkland Islands - State of the Environment Report". Falkland Islands Government and Falklands Conservation, Stanley. Retrieved 2010-06-05.
- P Stone, PC Richards, GS Kimbell, RP Esser & D Reeves (2008). "Cretaceous dykes discovered in the Falkland Islands: implications for regional tectonics in the South Atlantic". Journal of the Geological Society 165 (1): 1–4. doi:10.1144/0016-76492007-072.
- Southby-Tailyour, Ewen - Falkland Island Shores