Princess Consort of Monaco from 1662 to 1678 as the wife of Prince Louis I, and a mistress of Louis XIV of France in 1666. She was the daughter of Marshal, Antoine Duc de Gramont and Françoise Marguerite du Plessis de Chivré , a niece of Cardinal Richelieu.
Catherine Charlotte was educated in a fashionable convent school, the Visitation Faubourg Saint Jacques in Paris, where many daughters of the aristocracy were educated. She was described as a sophisticated, vivacious, strong-willed beauty. She fell mutually in love with her cousin, Antonin Nompar, Marquis de Puyguilleim, and when her father refused his permission for them to marry, they became lovers .
In March 1660 at the Chateau de Pau, Catherine married Louis de Grimaldi, Duc de Valentinois, the heir to the Principality of Monaco, who was described as "a glorious and avaricious Italian". They eventually had six children. Their marriage was arranged to strengthen the alliance between Monaco and France against Spain . Catherine Charlotte's family had connections at the French court and Louis was impressed by her beauty. She became Princess Consort of Monaco in 1662 when her husband succeeded to the throne. Catherine Charlotte was forced to accompany him to Monaco against her will, but Puyguilleim accompanied her on the way in disguise. She remained in Monaco for three unhappy years as she missed life at Court. The Prince and Princess of Monaco returned to Versailles in 1665 where Catherine Charlotte was appointed lady-in-waiting to the Duchesse d'Orleans, the former Princess Henrietta of England, sister-in-law of Louis XIV. Her aunt, Suzanne Charlotte de Gramont, Marquise de Saint Chaumont, was also a member of Henrietta's household as the governess of her two daughters. She continued her love affair with Puyguilleim, but also became involved in a love affair with the Duc de Guiche. She was renowned for her beauty and wit and attracted many lovers.
Madame de Sévigné described her as "greedy for pleasure", and she was nicknamed Catherine the Torrent. Princess Henrietta encouraged Catherine Charlotte to have an affair with the king to attract him away from his mistress Louise de la Vallière. The king's affair with Catherine Charlotte resulted in a public scandal as her other lovers, de Guiche and Puyguilleim, threatened a duel which led them all to be banished. She returned to Monaco, where she lived a quiet life and remained for four years until she was offered a position as lady-in-waiting to the king's mistress, Madame de Montespan. Her tenure ended the following year, but she was given her own house in Paris, where she was able to stay. During the following years, however, she fell ill with a progressive cancer. She died in Paris on 4 June 1678, and was buried Convent of the Capuchins.