Born Charlotte Louise Juliette Louvet in Constantine, Algeria, she was the bastard daughter of Marie Juliette Louvet (1867 - 1930), and Prince Louis II of Monaco (1870 - 1949).
Charlotte's mother was married to, in 1885, Achille Delmaet, 1860-1914, a photographer. Later divorced, they had two children: Georges, 1884-1955, and Marguerite, 1886-1894. At some point, Louvet moved to Algeria, where she worked as a cabaret singer or a laundress (sources differ) and met the heir to the Monegasque throne. Though it is sometimes alleged that a marriage between the two occurred, Charlotte, born in 1898, was declared an illegitimate child. Though he took full responsibility for his daughter's upbringing, eventually Prince Louis left Juliette to return to his duties in Monaco.
A political crisis loomed for the Prince because, without any other heir, the throne of Monaco would pass to the duke of Urach, a German prince, related through Prince Albert's aunt, Florestine.
To ensure this did not happen, on November 15, 1911 a law was passed recognizing Charlotte as Louis's daughter, and making her part of the sovereign family. This law was later held to be invalid under the 1882 statutes. Thus another law was passed in 1918 modifying the statutes to allow the adoption of an heir, with succession rights. Charlotte was adopted by Louis in 1919, and became Charlotte Louise Juliette Grimaldi, Hereditary Princess of Monaco, and Duchess of Valentinois.
A year after being recognized as princess, Charlotte's marriage was arranged to Count Pierre de Polignac (1895 - 1964) of Guidel, Morbihan, Brittany, France who, by ordinance of Louis II, took the Grimaldi name and received the title of Prince of Monaco. They would have two children:
While her father, Prince Louis II, was still living, on May 30, 1944 Charlotte ceded her rights to the throne of Monaco to her son Rainier subject to the stipulation that he did not predecease her.
Late in life she went to college, obtaining a degree in social work. After her son assumed the throne, Princess Charlotte moved to live at Marchais, the Grimaldi estate outside of Paris. Despite the objections of her children who feared for her safety, she turned the estate into a rehabilitation centre for ex-convicts.
Princess Charlotte died in Paris, France.