Disocactus is a genus of epiphytic cacti in the tribe Hylocereeae found in Central America, the Caribbean and northern South America. It should not be confused with Discocactus, which is a different genus.
Species of Disocactus grow in tropical regions either on trees as epiphytes or on rocks as lithophytes. They have two distinct growth habits. Species such as D. phyllanthoides have stems which are round at the base but then become flattened and leaflike. Other species, such as D. flagelliformis have stems which are round throughout their length.
The boundaries of the genera in the tribe Hylocereeae have been subject to considerable change and uncertainty, which is reflected in the number of names which have been used for Disocactus: