Marguerite Borel known as Camille Marbo (French pronunciation: [kamij maʁbo]; 11 April 1883 – 5 February 1969) née Marguerite Appell, was a 20th-century French writer, president and laureate of the Prix Femina in 1913 and president of the Société des gens de lettres.

Daughter of mathematician, Paul Appell (1855–1930), Camille Marbo was given the name Marguerite Appell.

In 1901, she married the mathematician and politician Émile Borel (1871–1956).

In 1906, she created La Revue du mois, a scientific and literary journal, with her husband. The publication allowed contributors the opportunity to choose and discuss subjects as they pleased. Marguerite Borel personally took charge of the critiques of plays, novels, and various chronicles.

When she began writing novels, she chose the pseudonym Camille Marbo, the name Marbo taking the first three letters of her first name Marguerite and the first two of her last name Borel.

In 1913, Camille Marbo was awarded the Prix Femina, then called Prix de la Vie heureuse, for her first novel La statue voilée.

During the First World War, she set up the Comité de secours national, the national relief committee with her father. She also founded and ran a temporary hospital in Paris, which earned her the Medal of French Gratitude. In 1916, she was asked to participate in the organization of women in the workforce in place of the men who had gone to battle. Benefiting from her experience as head of the hospital, she created a recruitment centre for women, which auditioned, tested, and employed both salaried employees and volunteers in the services sector. More than 20,000 women were employed through this program. The treatise she published in 1919, "Mobilization féminine en France", documents the contribution of these women to the Allied victory. This document is notable for its unique content as well as its methodical and professional form. It is carefully contextualized and enriched with statistics.

She wrote about forty other novels, some monographs and memoirs.