Gideon Curtis Moody (October 16, 1832 – March 17, 1904) was an attorney and politician, elected in 1889 as a Republican United States Senator from South Dakota.

He also had served five years as an associate justice of the Dakota Territory Supreme Court, from 1878 to 1883, before entering private practice for a period as general counsel for Homestake Mine.

When South Dakota joined the Union on November 2, 1889, Moody, one of the two senators chosen by the state legislature, took office.

They had five children together: Helen Eliot (1856–1940), married Mr. Dickinson; Charles C. (1858–1906), James Chaudoin (1862–1919), Burdette (1866–1946), and Warner Moody (1876–1906).

In 1878, Moody was appointed as an associate justice of the Dakota Territory Supreme Court, serving until 1883.

In 1883 he resigned his judicial position to enter private practice, hired as general attorney for the Homestake Mine.