Pap Ndiaye is the son of a Senegalese father and French mother, and also the brother of novel writer Marie Ndiaye. He was a student of the Ecole Normale and holds an agrégation in history, discovering black studies for the first time in the United States, at Virginia University. Having taken a meritocratic path and claiming himself to be a “universalist republican”, he was initially reluctant to take on the subject. He then became a lecturer at the School for Advanced Studies in the Social Sciences lecturing on the social history of the United States, and started to write about the question of minorities in France. This led him to take part in creating the Action Committee for the Promotion of Diversity in France and the Representative Council of France's Black Associations (CRAN). After being a faculty member at the Paris Institute of Political Studies (Sciences Po), in 2021 he was appointed head of the Palais de la Porte Dorée, which includes the Musée de l’Histoire de l’immigration.

In 2008, Pap Ndiaye published La condition noire: Essai sur une minorité française, (The Black Condition: Essay on a French Minority) a work often considered to have founded French black studies. He analyses the evolution of the controversial notion of “race” in the history of social sciences, in particular through a comparison with the United States. He has no hesitation in articulating his historian reflection, touching upon his own experience more discreetly: his essay is thus accompanied by a novel, “Les sœurs” (The Sisters), by his sister Marie Ndiaye. In 2012, he published another noteworthy book, Obama dans l’Amérique noire (Obama in Black America), where he questions the opportunity for French black people to access political responsibilities. 

In 2021 Pap Ndiaye was appointed head of the Palais de la Porte Dorée, which includes the Musée de l’Histoire de l’immigration. Today he wants to make this museum a reference in the field of scientific research on the history of immigration. But also a place for calm debate on questions that often still disturb French society. Under his direction, slavery and colonial questions will have a larger place in the permanent collection. The collection will be entirely redevised, in particular to include the 18th century, the time of the slave trade. Far from controversies, Pap Ndiaye, who considers his appointment to be a symbol, thereby wishes to create a place dedicated to education but also emotion and amazement, as for any museum.