Alexis Fontaine, known as Alexis Fontaine des Bertins (13 August 1704 – 21 August 1771) was a French mathematician. He was a patron and teacher of Jean-Jacques de Marguerie.

Fontaine was born in Claveyson. He first got a taste for maths by reading the Géométrie de l'infini of Fontenelle and gave solutions to the problems of the tautochrone curve, the brachistochrone curve and orthogonal trajectories. He was elected a member of the Académie des sciences in 1733. He died, aged 67, in Cuiseaux.

• Mémoires donnés à l'Académie royale des sciences, non imprimés dans leur temps (1764)
• Traité de calcul différentiel et intégral, par M. Fontaine, de l'Académie royale des sciences, pour servir de suite aux mémoires de la même Académie (1770)

• Biography and bibliography
• R Taton, Biography in Dictionary of Scientific Biography (New York 1970-1990).
• J M C de Condorcet, Eloge de M Fontaine, Histoire de l'Académie royale des sciences 1771 (Paris, 1774), 105-116.J L Greenberg, Alexis Fontaine's route to the calculus of several variables, Historia Math. 11 (1) (1984), 22-38.
• J L Greenberg, Alexis Fontaine's integration of ordinary differential equations and the origins of the calculus of several variables, Ann. of Sci. 39 (1) (1982), 1-36.
• J L Greenberg, Alexis Fontaine's 'fluxio- differential method' and the origins of the calculus of several variables, Ann. of Sci. 38 (3) (1981), 251-290.

 This article incorporates text from a publication now in the public domain: Bouillet, Marie-Nicolas; Chassang, Alexis, eds. (1878). Dictionnaire Bouillet (in French). {{cite encyclopedia}}: Missing or empty |title= (help)