Claude Auguste Thomassin (1865–1942) was a French bow maker, or archetier.
Son of Louis Thomassin with whom he learned his craft in Mirecourt. In his early career, he worked for the shop of Gand & Bernadel. Many bows from this period are stamped “Gand & Bernadel”. In 1901 the family firm of Gand & Bernadel was taken over by Caressa & Français. It was at this point that Claude Thomassin set up his own atelier at Rue de Paris in Paris. Although he continued to produce some bows for his former employers, much of his output from 1901 onwards was branded with his name “Claude Thomassin” or sometimes “C.Thomassin à Paris”.
Thomassin has been called one of the best makers of his generation.