|Reign||20 June 1856-10 September 1889|
|Predecessor||Florestan I of Monaco|
|Successor||Albert I of Monaco|
|Spouse||Antoinette de Mérode|
|Issue||Albert I of Monaco|
|Father||Florestan I of Monaco|
|Mother||Maria Caroline Gibert de Lametz|
|Born||8 December 1818|
|Died||10 September 1889|
Charles was married on 28 September 1846 to Antoinette de Mérode-Westerloo. He was succeeded by his son Albert I of Monaco. During his reign, the towns of Menton and Roquebrune, constituting some 80 percent of Monegasque territory, were formally ceded to France, paving the way for formal French recognition of Monaco's independence.
Under Charles III, the Principality of Monaco increased its diplomatic activities; for example, in 1864, Charles III concluded a Treaty of Friendship with the Bey of Tunis, Muhammad III as-Sadiq, which also regulated trade and maritime issues.