Robert S. Brookings (born January 22, 1850, Cecil county, Maryland, U.S.—died November 15, 1932, Washington, D.C.) was an American businessman and philanthropist who helped establish the Brookings Institution at Washington, D.C.
Brookings entered a St. Louis, Missouri, woodenware company at the age of 17. Four years later he and his brother opened their own woodenware firm and during the next 25 years extended their interests into real estate and the lumbering and transportation industries.
Following his retirement in 1896, Brookings devoted his time to the development of Washington University in St. Louis. As president of the university corporation (1897–1928) he helped relocate the school, induced wealthy St. Louis citizens to contribute money for buildings and endowments, and helped raise the medical school to a position of academic excellence. He was one of the original trustees of the Carnegie Endowment for International Peace and during World War I served as chairman of the price-fixing committee of the War Industries Board. After the war he became the first board chairman of the Institute for Government Research and helped found the Institute of Economics and the Brookings Graduate School of Economics and Government. In 1927 these three organizations were merged and named the Brookings Institution in his honour.