Ixoroideae is a subfamily of the Rubiaceae family. Based on both morphological and molecular characters, Rubiaceae has been divided into three subfamilies - Ixoroideae, Cinchonoideae, and Rubioideae. Ixoroideae and Cinchoinoideae are more closely related. Members of Ixoroideae are morphologically diverse so no shared derived characters have been established for its classification. Introduction of molecular analyses to systematics dramatically improved tribal classification within the subfamily. Present tribal classification within this subfamily is mainly supported through molecular analysis of chloroplast DNA.
Ixoroideae consists of 27 tribes that include several economically valuable genera. Well-known genera within the subfamily include Ixora and Gardenia, both popular ornamentals, but economic value is centered on the genus Coffea, cultivated for coffee production. Three species are generally used for cultivation - Coffea arabica, Coffea robusta, and Coffea liberica