Jacques I was Prince of Monaco from 1731 to 1733. He was also Duke of Valentinois from 1716 until 1733, and Count of Thorigny. For ten months preceding his accession, he had served as prince consort to his wife, Louise Hippolyte, Princess of Monaco.

Duke of Valentinois is a title of nobility, originally in the French peerage. It is currently one of the many hereditary titles claimed by the Prince of Monaco despite its extinction in French law in 1949. Though it originally indicated administrative control of the Duchy of Valentinois, based around the city of Valence, the duchy has since become part of France, making the title simply one of courtesy.