Finasseur (1902–1909) was a French Thoroughbred racehorse who, at age three, won the two most prestigious races in France. He was bred by Edmond Blanc at his Haras de Jardy stud farm at Marnes-la-Coquette about sixteen kilometers west of central Paris and purchased for racing by Michel Ephrussi, a wealthy businessman connected to the Rothschild banking family of France.Ephrussi entrusted the colt's race conditioning to trainer James d'Okhuysen.