William de la Barre (April 15, 1849, in Vienna – March 24, 1936, in Minneapolis) was an Austrian Empire-born civil engineer who developed a new process for milling wheat into flour, using energy-saving steel rollers at the Washburn-Crosby Mills (now known as General Mills, Inc.) in Minneapolis, and later served as chief engineer for the first hydroelectric power station built in the United States, at Saint Anthony Falls, also in Minneapolis.

De la Barre immigrated to the United States in October 1866, landing in New York, then settling in Philadelphia, Pennsylvania, where he found employment as a draftsman and engineer.

[1] While at the Centennial Exposition in Philadelphia, de la Barre had learned that a new process for milling flour had been invented in Europe that involved passing the grain through a series of rollers, rather than the large round millstones used in America.

On his return to Minneapolis, de la Barre designed rollers made from steel instead of porcelain.

After they were bought out by Northern States Power, De la Barre served in NSP management until he died at eighty-six in 1936.