Ker-Xavier Roussel (December 10, 1867 - June 6, 1944) was a French painter associated with Les Nabis.

Born François Xavier Roussel in Lorry - lès - Metz, Moselle, at age fifteen he studied at the Lycée Condorcet in Paris; alongside his friend Édouard Vuillard, he also studied at the studio of painter Diogène Maillart. In 1888 he enrolled in the École des Beaux - Arts, and soon began frequenting the Académie Julian where Maurice Denis and other students formed the group Les Nabis.

He is best known for paintings of French landscapes usually depicting women, children, nymphs and fauns in bucolic settings. In 1899, Roussel, Vuillard, and another close friend, Pierre Bonnard, traveled to Lake Como, Venice and Milan.

In 1926 Ker - Xavier Roussel won the Carnegie Prize for art.

Ker - Xavier Roussel died in 1944 at his home in L'Étang - la - Ville, Yvelines.

Roussel is mentioned in Gertrude Stein's Autobiography of Alice B. Toklas, Chapter 3. There she recounts an exchange he had with Theodore Duret in Vollard's shop at an uncertain date after 1904. Roussel complained of the lack of recognition that he and the other Nabi painters had to contend with. Duret consoled him by pointing out his incompatibility with the manners and fashions of the bourgeois world and the differences between "art" and "official art".