P. porphyrae can refer to two different species. The specific epithet porphyrae (πορφυρα) means 'purplish-red.'
- Polaribacter porphyrae , a bacteria in the family Flavobacteriaceae
- Pontisma porphyrae , a oomycete in the family Pontismataceae
- Pythium porphyrae, a oomycete in the family Pythiaceae that causes red rot disease in many edible seaweeds