Mammillaria spinosissima (/mæmɪˈlæriə spɪnoʊˈsɪsimə/), also known as spiny pincushion cactus, is a type of cactus endemic to the central Mexican states of Guerrero and Morelos, where they grow at elevations of approximately 1,600 to 1,900 meters (5,200 to 6,200 ft). The species was described in 1838 by James Forbes, gardener of the Duke of Bedford. Botanist David Hunt collected a specimen in 1971, when he located one near Sierra de Tepoztlan, Mexico.