French multinational pharmaceutical and healthcare company headquartered in Paris, France. Originally, the corporation was established in 1973 and merged with Synthélabo in 1999 to form Sanofi-Synthélabo. In 2004, Sanofi-Synthélabo merged with Aventis and renamed to Sanofi-Aventis, which were each the product of several previous mergers. It changed its name back to Sanofi in May 2011. The company is a component of the Euro Stoxx 50 stock market index.

Sanofi engages in the research and development, manufacturing, and marketing of pharmacological products, principally in the prescription market, but the firm also develops over-the-counter medications. The corporation covers seven major therapeutic areas: cardiovascular, central nervous system, diabetes, internal medicine, oncology, thrombosis, and vaccines (it is the world's largest producer of the last through its subsidiary Sanofi Pasteur).