Rubia is a genus of flowering plants in the Rubiaceae family. It contains around 80 species of perennial scrambling or climbing herbs and subshrubs native to the Old World. The genus and its best-known species are commonly known as madder, e.g. Rubia tinctorum (common madder), Rubia peregrina (wild madder), and Rubia cordifolia (Indian madder).

Rubiá is a municipality in the Spanish province of Ourense. It has a population of 1734 (Spanish 2001 Census) and an area of 101 km².