John Grist Brainerd (1904 – February 1, 1988) was an American electrical engineer who served as principal investigator on the project to build ENIAC, the first general-purpose electronic digital computer. Later, he was dean of the Moore School of Electrical Engineering at the University of Pennsylvania. Brainerd was the recipient of the IEEE Founders Medal in 1975 "for his leadership in electronics in fields encompassing computer technology, high frequency techniques, engineering education, and national and international electrical standardization."