Merck may refer to:
- Merck KGaA, (EMD Chemicals in the United States and Canada), a German-based chemical and pharmaceutical company
- Merck Serono (EMD Serono in North America), a pharmaceutical division of Merck KGaA
- Merck family, a family of pharmacists who eventually founded Merck KGaA
- Merck & Co., Inc. (Merck Sharp & Dohme outside North America), an American pharmaceutical company created after World War I from assets forfeited by Merck KGaA, though the two are unassociated
- Merck Manual of Diagnosis and Therapy, a medical textbook published by Merck & Co.
- Merck Index, an encyclopedia of Chemistry, published by Merck & Co.
- Merck Veterinary Manual, a reference manual of animal health care published by Merck & Co. and Merial Limited
- People
- Merck family, original owners of the chemical companies above
- Ernst Merck (1811–1863), German businessman and politician
- George W. Merck (1894-1957), American president of Merck & Co.
- Heinrich Emanuel Merck (1794–1855), German apothecary whose descendants were the founders of Merck chemical companies
- Johann Heinrich Merck (1741–1791), German author and critic
- William Merck (1852-1925), British commissioner in India
- Other uses
- Merck Finck & Co., a German private bank
- Johann-Heinrich-Merck-Preis, a literary prize of Hesse, Germany
- Merck Records, an IDM and experimental hip hop record label based in Miami, Florida, USA
- Merck-Saint-Liévin, a commune in the Pas-de-Calais department, France