Known primarily as a jeweler in the vanguard of Art nouveau and an important collector of the Impressionists, Henri Vever (1854-1942), as his private diaries make clear, was also a foremost connoisseur of Japanese art in fin-de-siècle France, “the most passionate of all,” to Edmond de Goncourt. Well-connected to networks of dealers, museum officials, publications, and sites of sociability such as the dîners japonais, Vever figures among the most prominent members of a second wave of Parisian enthusiasts of Japanese art, active from approximately 1880 to 1900. Under the tutelage of the Japanese art dealers Hayashi Tadamasa and Siegfried Bing and the fine art printer Charles Gillot, Vever constituted a renowned collection of not only Japanese prints but also other art objects previously disregarded by collectors. Vever’s multiple and intersecting identities as luxury craft producer, leading member of professional associations, art historian and critic, collector, and Republican mayor placed him at the forefront of efforts to legitimate the collection and appreciation of Japanese art in France. His diaries also underscore the connections between the worlds of Japanese and Impressionist art collectors, and between proponents of japonisme and Art nouveau. Further, they highlight the importance of the 1900 Paris Exposition universelle as a triumphant moment for japonisme in France, just as they signal the shift on the part of some japonisants, at the same time, from Japanese art towards the decorative arts of the Islamic world.