John Ripley Freeman (1855–1932) was an American civil and hydraulic engineer. Freeman was born in West Bridgton, Maine and received his undergraduate degree from MIT in 1876. He is noted for his efforts to design and build the Charles River Dam, advising the government on dam and lock foundations for the Panama Canal, and influencing the design of MIT's new campus in Cambridge, Massachusetts. He was also the founder and president of Massachusetts Mutual Fire Insurance Co.. He also served on the National Advisory Board on Aeronautics during World War I.