Gelsemiaceae is a family of flowering plants, belonging to order Gentianales. The family contains only two genera: Gelsemium and Mostuea. Gelsemium has three species, one native to Southeast Asia and southern China and two native to Southeastern United States, Mexico and Central America. The eight species of Mostuea are native to tropical South America, Africa, and Madagascar.

The two genera were formerly classified in family Loganiaceae; family Gelsemiaceae was described in 1994, and is distinguished by having no latex in the plants, and heterostylous flowers with yellow-white corollas, no latex or stipules, and superior ovaries.