Marguerite de Witt-Schlumberger (20 January 1853 – 23 October 1924) was a French campaigner for pronatalism, alcoholic abstinence, and feminism.

[1] She married into the Schlumberger family and became a powerfully influential matriarch and the mother of several sons who achieved notability in their own right.

The name "de Witt" disclosed the family's Dutch origins, as a result of which they also were members of France's minority Protestant community.

She campaigned with energy for the abolition of "regulated prostitution" and presided over the International Commission for a Single Standard of Morality and Against the White Slave Trade.

The moral crusades of earlier decades had opened discussion on previously taboo topics, such as legal double standards for men and women.

[12] In 1917, suffragists presented a petition to the Chamber of Deputies asking for voting equality in return for the work women had done during the war.

Witt-Schlumberger responded for the last time after the end of the war asking the President to uphold his word at the upcoming Paris Peace Conference.

[20][21] Drawing delegates from Allied countries aligned with the IWSA, the conference proposed to U.S. President Woodrow Wilson and Prime Minister of France, Georges Clemenceau, that women be appointed to participate on advisory committees to the conference and be allowed to present a plea for women's equality.

They asked for trafficking of women and children to be banned, for education to be a protected right, and for global suffrage to be recognized in principle.

[19] In 1920, Witt-Schlumberger was appointed as the sole female member of the Conseil supérieur de la Natalité (CSN) (Birth Council) and argued that women should be able to protect themselves from diseased or unfit fathers.

He was from a family of Protestant industrialists who traced their wealth back to Paul's grandfather, Nicolas Schlumberger [fr] (1782–1867), who had made a fortune as a textiles (cotton) baron.

[2] Conrad and Marcel Schlumberger qualified as a physicist and engineer, respectively, becoming noteworthy for their inventions in the fields of geophysics and petroleum technology.