This rocky islet on Lake Geneva has been occupied since the Bronze Age for strategic reasons. The castle as it is today dates from the 13th century. It was built by the House of Savoy to control the passage along Lake Geneva. The fortress was also used as an arsenal, prison, and temporary residence of the Dukes of Savoy.

One scene of Jean-Jacques Rousseau’s sentimental novel "Julie or the New Heloise" (1762) was set in Chillon Castle. Intrigued, Lord Byron visited the castle and found the inspiration to write "The Prisoner of Chillon" (1816). This work describes the sufferings of François Bonivard (1493-1570), a prior that was imprisoned for his anti-Savoy positions.

There have been recent alterations to improve the visit to the Castle and its dungeon, its private chapel, its ancient weapons and its lookout path. Chillon Castle remains a highly valued site: it attracts more than 300,000 visitors a year, 75% of which are foreign tourists.