Fort Boyard is a fort located between in the île d'Aix and île d'Oléron in the Pertuis d'Antioche straights, on the west coast of France.

The construction of this fort had already been considered since the completion of the arsenal in 1666, but Vauban famously advised Louis XIV against it saying "Sir, it would be easier to catch the moon with the teeth than take on such an endeavour in such a location".

The fort was actually started under Napoleon in 1801, in order to protect the coast (and especially the arsenal of Rochefort) from possible incursions by foreign (and especially British) navies. At that time, cannons only had a limited range, and the distance between the two islands of Aix and Oleron was too large to block the passage.

Following difficulties in establishing a firm base (stone blocks had to be installed on the sandy sea bed during low tide but they still sank under their own weight) the project was adjourned in 1809. Contruction started again in 1837 under Louis-Philippe, following renewed tensions with Great Britain, and was completed in 1857.

Fort Boyard had a complement of 250 men. It is 61 meters long, 31 meters wide, and its walls are 20 meters high.

By the time of its completion however, the range of cannons had markedly increased, making the Fort unnecessary.

Under the Commune, the fort was converted to a prison, before being abandoned a few years later.

Since 1990, Fort Boyard has been used as the location for a television game show of the same name. A contraption similar to an oil rig has been installed on the side in order to facilitate access to television crews.

Fort Boyard is now shown on Ftn for the new series.