former French chemical manufacturer and leading producer of organic chemicals, synthetic fibres, and pharmaceuticals. It merged with Hoechst Aktiengesellschaft in 1999 to create the French-German pharmaceutical firm Aventis.

The company originated as a dyestuffs manufacturer in 1801 under the name Maison Debai-Extraits Tintoriaux and in 1895 was established as Société Chimique des Usines du Rhône (“Chemical Factories of Rhône”). In 1928 it merged with Établissements Poulenc Frères (“Poulenc Brothers”), the pharmaceutical house established by Camille Poulenc (1864–1942), the founder of the French pharmaceutical industry and a collaborator of Pierre (Curie, Pierre) and Marie Curie (Curie, Marie). The new Société des Usines Chimiques Rhône-Poulenc immediately founded subsidiaries to develop pharmaceutical specialties and new techniques for the manufacture of synthetic textiles.

When France entered the European Economic Community in 1957, Rhône-Poulenc became active in the reorganization of the French chemical industry. In 1961 it absorbed Celtex, a major synthetic-fibre producer, and went on to become a leader in that field in France. It was nationalized by the French government in 1982 but returned to private ownership in 1993. Although synthetic fibres accounted for a larger share of company production, the French public still identified Rhône-Poulenc with its drug products. In 1995, one of its main subsidiaries, Rhône-Poulenc Rorer, Inc., acquired Fisons, a major British drug manufacturer.

The company also expanded into the production of plastics, fine specialty chemicals, films for packaging, electromagnetic tapes, and communications and copying systems, as well as textiles, glues, paints, varnishes, and agricultural chemicals. While the bulk of the firm's sales were in France, it developed important markets in other western European countries, the Americas, Africa, Australia, the Middle East, and the Far East, many of which later contributed to Aventis's global reach.