The Femina Prize is awarded in three categories -- best French novel, best foreign novel and best essay -- by an all-woman jury.
The Femina committee awarded its prize for best French novel to Cameroonian author Leonora Miano for "La Saison de l'ombre" ("The Season of Darkness") about the loss of loved ones experienced by sub-Saharan Africans during the slave trade.
Miano, who has lived in France since 1991, used her acceptance speech to denounce racist insults directed at the country's justice minister.
"It's not only the minister who is insulted, but all black people who are reduced to being animals (by this)," Miano said, referring to two occasions in the past month when Christiane Taubira has been publicly compared to a monkey.
Miano's novel "The Season of Darkness" ("La Saison de l'ombre") explores the loss of loved ones by sub-Saharan Africans during the slave trade.
"I am very happy, for everyone who feels a little avenged today," she said at the award ceremony in Paris. Miano has lived in France since 1991.
Earlier on Wednesday, Taubira made her first public comments about the racist taunts, warning of a rising tide of racism in France.
"It is not about careless little slips of the tongue, it is much more serious than that," she said in an interview with left-wing daily Liberation.
"Inhibitions are disappearing, dykes have been breached," she said.
The first time Taubira was compared to a monkey was by a group of children whose parents had taken them on a protest against gay marriage.
On the second occasion, the insult came from an electoral candidate of the far right National Front who wrote on her Facebook page that she would prefer to see the minister "swinging from the branches rather than in government".
Best essay went to Jean-Paul and Raphael Enthoven for a work entitled "Dictionnaire amoureux de Proust".