Grünenthal is a pharmaceutical company headquartered in Aachen in Germany. It was founded in 1946 as Chemie Grünenthal and has been continuously family-owned. The company was the first to introduce penicillin into the German market in the postwar period, after the Allied Control Council lifted its ban.

Grünenthal became infamous in the 1950s and 1960s for the development and sale of the teratogenic drug thalidomide, marketed as the sleeping pill Contergan and promoted as a morning sickness preventive. Thalidomide caused severe birth defects, miscarriages, and other severe health problems. Though these side effects were proven conclusively in 1959, and 1962, Grünenthal continued marketing the drug well into the 1970s and 1980s.

The company generates more than 50 percent of its income with pain medications such as Tramadol. The company has two offices in Germany as well as subsidiaries in Europe, Latin America, the US, and China. In November 2016, the company acquired Thar Pharmaceuticals and in 2018 Averitas Pharma.