落花生属（学名：Arachis）是蝶形花科下的一个属，为低矮草本植物。该属共有约19种，大部分产自巴西。

Arachis is a genus of about 70 species of annual and perennial flowering plants in the pea family (Fabaceae), native to South America, and was recently assigned to the informal monophyletic Pterocarpus clade of the Dalbergieae. At least one species, the peanut (Arachis hypogaea), is a major food crop species of global importance; some of the other species are cultivated for food to a small extent in South America. Other species such as A. pintoi are cultivated worldwide as forage and soil conditioner plants, with the leaves providing high-protein feed for grazing livestock and a nitrogen source in agroforestry and permaculture systems.