Marie Dompnier is a French actress, singer and director born in 1980 in Toulouse, Haute-Garonne, in France, best known both in France and internationally for her role as Lieutenant Sandra Winckler in the TV series Witnesses (Les Témoins).

From 2000 to 2002, Dompnier took professional training as an actor in the Ateliers du Sapajou in Paris, Marie furthered her education in 2003, at the Centre Dramatique National in Poitiers. From 2002 to 2004, she also studied at the Conservatoire National Superieur d'Art Dramatique, 5th arrondissement of Paris. Dompnier joined the L’École régionale d’acteurs de Cannes in 2004, graduating in 2007.