Stephen Moulton Babcock was an American agricultural chemist. He is best known for developing the Babcock test, used to determine butterfat content in milk and cheese processing, and for the single-grain experiment that led to the development of nutritional science as a recognized discipline.

The Babcock test is an inexpensive and practical procedure to determine the fat content of milk. It is named after its developer, Stephen M. Babcock (1843–1931), professor at the University of Wisconsin.