John Wellborn Root, American architect, designed the Rookery Building and Monadnock Building (d. 1891)

John Wellborn Root (January 10, 1850 – January 15, 1891) was an American architect who was based in Chicago with Daniel Burnham. He was one of the founders of the Chicago School style. Two of his buildings have been designated a National Historic Landmark; others have been designated Chicago landmarks and listed on the National Register of Historic Places. In 1958, he was posthumously awarded the AIA Gold Medal.