古柯属（学名：Erythroxylum）是古柯科下的一个属，为灌木或小乔木植物。该属共有250种，分布于热带、亚热带地区。

Erythroxylum (Erythroxylon) is a genus of tropical flowering plants in the family Erythroxylaceae. Many of the approximately 200 species contain the drug cocaine; Erythroxylum coca, a native of South America, is the main commercial source of cocaine and of the mild stimulant coca tea. Another species, Erythroxylum vacciniifolium (also known as Catuaba) is used as an aphrodisiac in Brazilian drinks and herbal medicine.