Ptychadena newtoni is a species of frog in the Ptychadenidae family. It is endemic to the island of São Tomé in São Tomé and Príncipe and are founded up to an elevation of 600 metres. Its natural habitats are swamps, freshwater marshes, arable land, plantations, rural gardens, urban areas, heavily degraded former forest, ponds, and canals and ditches. It is threatened by habitat loss. The animal was described in 1886.