René-Yves Creston (25 October 1898 – 30 May 1964), born René Pierre Joseph Creston, was a Breton artist, designer and ethnographer who founded the Breton nationalist art movement Seiz Breur. During World War II he was active in the French Resistance.
Born in Saint-Nazaire, Creston studied art there and at Ancenis, followed by the École des Beaux-Arts in Nantes and Paris. In 1923, he was one of the founders with Jeanne Malivel and his wife Suzanne Creston, of Ar Seiz Breur (The Seven Brothers), which united dozens of Breton artists and designers in a movement to create a distinctive Breton avant-garde style. Creston participated in the decoration of the Pavilion of Brittany at the Exhibition of Decorative Arts in Paris in 1925. Creston and Malivel also collaborated on furniture designs shown there. After the early death of Jeanne Malivel in 1926, he became the principal coordinator of Seiz Breur until the end of 1944.
In 1927, in collaboration with the young sculptor Jules-Charles Le Bozec (1898–1973), he designed the costumes for three plays: Ar C'hornandoned, by Yann Bayon and Jean-Marie Perrot, Tog Jani by Yves Le Moal and Lina by Roparz Hemon, the first performance of which took place in January 1927. He also assisted in the publication of the art magazines Kornog and Keltia. He worked in woodcut, watercolor, oil, and designed earthenware and sculpture. He also illustrated the book Kan da Gornog by Youenn Drezen, for which he invented a new typeface.
Creston was also associated with the wider Breton nationalist movement. He wrote articles for the Breton nationalist journal Breiz Atao, and designed images for nationalist events. In 1929 he created a cabinet as a wedding present for the Breton nationalist leader François Debeauvais. However, after Debeauvais formed the separatist Breton National Party in 1931, Creston joined the rival moderate Breton Federalist League.