Marie Tonoir was born in Lyon and studied with the painters Joseph Guichard and Pierre Miciol before moving to Paris, where she attended Académie Julian and studied under Jules Lefebvre and Benjamin Constant. She started using her hyphenated name after marrying fellow artist Jean Caire circa 1886.

Tonoir was a figure painter throughout her career. In Lyon, society women at leisure and allegorical nudes were her subjects of choice; following a move to Caire’s hometown in the rural Ubaye valley, she turned her eye to men and women working in the fields. The Caire-Tonoirs, like many artists of their time, were intrigued by the so-called Orient, and travelled often to Algeria and Tunisia. Marie Tonoir spent several months between 1899 and 1900 in Biskra, an Algerian town known as the “Pont-Aven of the desert” for its popularity with painters. It was there that she painted the famous “Tête de femme Biskra,” a portrait reproduced on a French postage stamp in 2012. Tonoir also exhibited abroad, notably at the Tunisian Salon in Tunis, where she showed a painting of Salome.

Tonoir was a member of the Society of French Artists; the Union of Women Painters, Sculptors and Engravers; and the Society of Orientalist Artists. She won third prize at the 1892 Paris Salon.

Caire-Tonoir's paintings are in the collections of the Musée du Quai Branly – Jacques Chirac in Paris and Musée de la Vallée in Barcelonnette.