Hilaire Noël Sébastien Clément, known as Clément-Janin (1862–1947) was a French writer and art critic, specializing in the modern history of printmaking.

His first literary activities involved the posthumous publication of some of his father's works, and then donating his archives to the Musée d'Ethnographie du Trocadéro.

In the mid-1890s, he became attracted to the Positivist milieu, making the acquaintance of Édouard Pelletan [fr], and joining him in the process of establishing his publishing house, which was inaugurated in 1896.

Later, Pelletan would entrust him to collaborate with André Mellerio in the management of his magazine, L'Estampe et l'affiche [fr][1] In 1908, he was named curator and conservator of the modern prints department at the newly established Bibliothèque d’Art et d’Archéologie, initiated by the fashion designer, Jacques Doucet, who was also an art patron and collector.

[3] One of his last works was the Essai sur la bibliophilie contemporaine, issued in two volumes by René Kieffer [fr], in 1931 and 1932.