Oskar Dieter Alex von Rosenberg-Redé, 3rd Baron von Rosenberg-Redé, also known as Alexis, Baron de Redé, was a prominent French banker, aristocrat, aesthete, collector, and socialite. In 2003, he was appointed a commandeur of the Ordre des Arts et des Lettres for his restoration of the Hôtel Lambert, where he was known for hosting opulent costume balls. Involved in horse racing, in 1972 he won the Prix de Diane and came in second at the Prix de l'Arc de Triomphe.

The Hôtel Lambert is an hôtel particulier, a grand mansion townhouse, on the Quai Anjou on the eastern tip of the Île Saint-Louis, in the 4th arrondissement of Paris. In the 19th century, the name Hôtel Lambert also came to designate a political faction of Polish exiles associated with Prince Adam Jerzy Czartoryski, who had purchased the Hôtel Lambert.