Crawford H. Greenewalt (1902-1993) was an executive with the DuPont Company and president of the firm from 1948 to 1962.

Born on August 16, 1902 in Cummington, Massachusetts, Crawford H. Greenewalt was the son of Frank Lindsay Greenewalt (1865-1942) and Mary Elizabeth Hallock Greenewalt (1871-1950). He graduated from William Penn Charter School in Philadelphia and earned a Bachelor of Science degree in chemical engineering from Massachusetts Institute of Technology (MIT) in 1922. Immediately after graduating from MIT, Greenewalt began a lifelong career with the DuPont Company.

He began as a control chemist in the Philadelphia chemical works. He was soon promoted to group leader, research supervisor, and assistant director of research. As assistant director of the Chemical Department from 1939 to 1942, he set up the pilot plant for the production of Nylon.

In 1942, when the DuPont Company agreed to participate in the Manhattan Project, Greenewalt was named chief liaison, working with the physicists at the University of Chicago Metallurgical Laboratory, including Arthur Compton (1892-1962) and Enrico Fermi (1901-1954), who were developing techniques for plutonium separation. In December 1942, the DuPont Company signed an agreement with the U.S. government to design and construct a pilot plant-size reactor and to operate a plutonium production and separation facility. The site for this facility was to be in the desert of eastern Washington State, and the plant became known as the Hanford Engineer Works. By the spring of 1945, Hanford was the site of a full-scale plant producing plutonium that would be used in the atomic bombs exploded in New Mexico on July 16 and over Nagaski, Japan, on August 9, 1945.

After the war, Greenewalt was named head of DuPont's Explosives Department, and in 1948 he became president of the company, a position he held for fourteen years.