Carnegie Science, also known as the Carnegie Institution of Washington and formerly Carnegie Institution for Science, is an organization established to fund and perform scientific research in the United States. This institution is headquartered in Washington, D.C. As of June 30, 2020^[update], the Institution's endowment was valued at $926.9 million. In 2018, the expenses for scientific programs and administration were $96.6 million. American astronomer and astrophysicist John Mulchaey is the current president of the institution.

More than 20 independent organizations were established through the philanthropy of Andrew Carnegie and feature his surname.

In 2024, the "Carnegie Institution for Science" officially adopted the name "Carnegie Science", a name which has been used informally since 2007 when they first changed the name from "Carnegie Institution of Washington" to "Carnegie Institution for Science".

It is proposed to found in the city of Washington, an institution which ... shall in the broadest and most liberal manner encourage investigation, research, and discovery [and] show the application of knowledge to the improvement of mankind.

—Andrew Carnegie, January 28, 1902

When the United States joined World War II, Vannevar Bush was president of the Carnegie Institution of Washington. Several months prior to June 12, 1940, Bush persuaded President Franklin Roosevelt to create the National Defense Research Committee (later superseded by the Office of Scientific Research and Development) to coordinate the nation's scientific war effort. Bush housed the new agency in the Carnegie Institution's administrative headquarters at 16th and P Streets, Northwest, in Washington, D.C., converting its rotunda and auditorium into office cubicles. From this location, Bush supervised multiple projects, including the Manhattan Project. Carnegie scientists assisted with the development of the proximity fuze and mass production of penicillin.

John Mulchaey, an American astronomer and astrophysicist, is the institution's 12th president. Carnegie Science is composed of three scientific divisions on the East and West Coasts that center on life and environmental science, Earth and planetary science, and astronomy and astrophysics: Biosphere Sciences & Engineering, Earth & Planets Laboratory, and Observatories. In addition to facilities in the United States, Carnegie Science manages the Las Campanas Observatory in Chile.

Carnegie Science’s life and environmental science research activities are currently housed under the institution's Biosphere Sciences & Engineering Division and were historically housed under departments, including the Department of Embryology in Baltimore, MD and the Department of Global Ecology in Palo Alto, CA. The former Department of Plant Biology began as a desert laboratory in 1903 to study plants in their natural habitats. Over time, the research evolved to the study of photosynthesis. The department develops bioinformatics. Among its notable staff members are Nobel laureates Andrew Fire, Alfred Hershey, and Barbara McClintock.