Gaston Casimir Saint-Pierre (French, 1833-1916) was a painter of genre scenes and portraits, as well as a pastelist. He is best known for his very large decorative panels. He was a student of Leon Cogniet and Charles François Jalabert. He made his debut at the Salon de Paris in 1861 and exhibited at the Salon des Artistes Français. From 1883, he became a member of the Salon des Artistes Français and a member of its committee and jury. He received a medal "deuxième classe" in 1879. He was made "chevalier de la Légion d'honneur" in 1881 and "officer" in 1903. The French government bought several of his paintings during his lifetime.

Works by him are kept in museums in Amiens, Bayonne, Bordeaux, Châteauroux, Limoges, Lyon, Paris, Tarbes and Tourcoing.