Marie Charlotte Blanc (née Hensel; 23 September 1833 – 25 July 1881) was a German socialite and businesswoman.

Marie Charlotte Hensel was born on 23 September 1833 in Friedrichsdorf to working class parents.

While living in Monaco, Hensel helped her husband establish the casino in Monte Carlo.

After her husband's death, Hensel inherited 72 million francs and took control of the Monte Carlo Casino.

[1] At the age of 14 she entered service as a maid for French businessman François Blanc; his wife, Madeleine-Victoire Huguelin; and their two children, Camille and Charles, at their home in Bad Homburg vor der Höhe.