Robert Williams Wood (May 2, 1868 - August 11, 1955) was a physicist. Born Concord, Massachusetts, Wood was professor of experimental physics at Johns Hopkins University from 1901.

His fields of interest included:

• Raman spectroscopy;
• Field emission;
• Optics; and
• The manufacture of diffraction gratings.

Wood is probably best known for his work in discrediting the phenomenon of N rays.

Wood died in Amityville, New York.

He published a number of books including:

• Physical Optics (1905)
• How to Tell the Birds from the Flowers and Other Wood-Cuts: A Revised Manual of Flornithology for Beginners (1907) ISBN 0486205231

Biography book: Doctor Wood. Modern wizard of the laboratory. by William Seabrook (1941)