Maurice Joyant was the manager of the Paris branch of Boussod, Valadon et Cie. He was the nephew of the painter Jules-Romain Joyant.
Following Theo van Gogh's death in 1891, Joyant became buyer and director of the Paris branch of Boussod, Valadon et Cie. A lifelong friend of Henri de Toulouse-Lautrec, whom he met at the Lycée Fontanes in 1872-3, Joyant organised the first retrospective of Lautrec's work at Boussod, Valadon et Cie in 1893. Five years later Joyant held an exhibition of Lautrec's work at the Goupil Gallery in London.
In 1898 Joyant, along with the Italian printmaker Michele Manzi and art dealer Jean Boussod, formed Jean Boussod, Manzi, Joyant et Cie, concentrating on the publishing of prints. On Boussod's death in 1907 Manzi and Joyant opened their own gallery in Paris at 15 Rue de la Ville-l'Evêque. They held a posthumous retrospective of Lautrec's work in 1914. Joyant was largely responsible for persuading Lautrec's mother, the Comtesse Adèle de Toulouse-Lautrec, to give her collection to the Musée Toulouse-Lautrec at Albi. Joyant's biography of Toulouse-Lautrec was published in 1926-7.
In the 1890s a significant number of Whistler's paintings, watercolours, etchings and lithographs went through Joyant's hands. For example, in 1891 Arrangement in Grey and Black: Portrait of the Painter's Mother y101 was sent to Joyant for exhibition, and Joyant was involved in persuading the French State to purchase the painting. In this year Joyant was also involved in the sale of Nocturne: Blue and Gold - St Mark's, Venice y213. The following year Boussod, Valadon et Cie held a retrospective exhibition of Whistler's paintings in London at the Goupil Gallery, Nocturnes, Marines and Chevalet Pieces, and Joyant sent Nocturne: Black and Gold - The Fire Wheel y169 to be exhibited at the second exhibition of the Société Nationale des Beaux-Arts in the Champs de Mars. Boussod, Valadon et Cie held eight exhibitions of Whistler's work in London at the Goupil Gallery between 1895 and 1922.
Joyant, M., Henri de Toulouse-Lautrec, 1864-1901, 2 vols, Paris, 1926-27; Young, Andrew McLaren, Margaret F. MacDonald, Robin Spencer, and Hamish Miles, The Paintings of James McNeill Whistler, New Haven and London, 1980 ; MacDonald, Margaret F., James McNeill Whistler. Drawings, Pastels and Watercolours. A Catalogue Raisonné, New Haven and London, 1995 ; Whiteley, Linda, 'Boussod, Valadon and Cie', and 'Manzi-Joyant, The Grove Dictionary of Art Online, ed. L. Macy.