Robert Patterson Lamont was born in Illinois on December 1, 1867, became a businessman, and went to work in Chicago. During World War I, he served as chief procurement officer for the U.S. war effort.

Lamont became assistant commerce secretary in the administration of President Warren G. Harding, serving under Commerce Secretary Herbert Hoover. When Hoover entered the White House, he appointed Lamont commerce secretary; Lamont served in that position from 1929 to 1932, when he was succeeded by Roy D. Chapin. Robert Lamont died in Chicago, Illinois, on February 20, 1948.