Ruth Wyckliffe Stokes (October 12, 1890 or 1891 – August 27, 1968) was an American mathematician, cryptologist, and astronomer.

She earned the first doctorate in mathematics from Duke University, made pioneering contributions to the theory of linear programming, and founded the Pi Mu Epsilon journal.

She was principal of a school in Rock Hill, South Carolina, from 1913 to 1916, and head of mathematics at Synodical College in Fulton, Missouri, from 1916 to 1917.

[2][3] She completed her Ph.D. in 1931, supervised by Joseph Miller Thomas,[4] becoming the first person to earn a doctorate in mathematics at Duke.

As a response to World War II, in 1942, she instituted a program in cryptology, and began teaching navigation and astronomy to pilots in the United States Army Air Corps.