San Pedro cactus may refer to several species or infraspecies of cactus potentially containing mescaline, particularly:
- Trichocereus macrogonus var. pachanoi, synonyms including Trichocereus pachanoi and Echinopsis pachanoi
but also:
- Echinopsis cuzcoensis
- Echinopsis lageniformis
- Trichocereus macrogonus
- Trichocereus macrogonus var. macrogonus, synonyms including Trichocereus peruvianus and Echinopsis peruvianus