Callulina kreffti, commonly known as Krefft's secret frog or Krefft's warty frog, is a species of frog in the family Microhylidae. It is found in the Eastern Arc Mountains in Tanzania and in southern Kenya. Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical moist montane forests, rural gardens, and heavily degraded former forest. It is threatened by habitat loss.