Robert Williams Wood (May 2, 1868 - August 11, 1955) was an American physicist and inventor. He is often cited as being a pivotal contributor to the field of optics and a pioneer of infrared and ultraviolet photography. Wood's patents and theoretical work shed much light on the nature and physics of ultra-violet radiation and made possible the myriad of uses of uv-fluorescence which became popular after World War I. Although a physicist, Wood also authored two books aimed at children.