John Ruel Manning (April 16, 1897 – August 4, 1939) was an American chemist and technologist. During employment with the United States Bureau of Fisheries (BOF), he became a noted writer and lecturer on the use of fishery products in animal nutrition and pioneered fishery products utilization research, overseeing the BOF's investigations into the use of various applied sciences in the utilization and preservation of fishery products.