In 1885 he returned to France to accept the chair of languages and literature of southern Europe in the Collège de France.
He became influential and known widely, and in 1894 he was Taylorian lecturer at Oxford University.
He was elected corresponding member of the Spanish Royal Academy of the Language, and was appointed a Knight Commander of the Order of Charles III, and in his own country became an officer of public instruction, a member of the Institute of France (1910), and a Knight of the Legion of Honor.
After 1874 Morel-Fatio was a contributor to the Romania, and after 1899 one of the directors of the Bulletin Hispanique.