Laconia, also known as Lacedaemonia, was in ancient Greece the portion of the Peloponnesus of which the most important city was Sparta. In modern times, Laconia has the legal status as a prefecture of Greece with Sparta being its administrative capital.

The English word laconic is derived from the name of the region by analogy - to speak in a concise way, as the Spartans were reputed by the Athenians to do.

Laconia is also a city in New Hampshire, United States of America: see Laconia, New Hampshire.

Laconia was the Cunard liner involved in the Laconia incident during World War II. The ship was torpedoed on September 12, 1941 by a U-boat which rescued the survivors but was itself attacked by an American aircraft four days later whilst towing lifeboats filled with people and prominently displaying a Red Cross flag. The German admiralty subsequently issued the "Laconia order" which forbade U-boats from helping the survivors of ships which they had sunk, and for which Admiral Karl Dönitz was controversially prosecuted at the end of the war.