Sanphet (Thai: สรรเพชญ, IPA: [sǎn.pʰét]; Sanskrit: सर्वज्ञ Sarvajña ; "Omniscient", referring to the Buddha) was a Thai royal title. It may refer to:
- Kings of Ayutthaya:
- Mahathammarachathirat (king of Ayutthaya) or Sanphet I (1509–1590)
- Naresuan or Sanphet II (1555–1605)
- Ekathotsarot or Sanphet III (died 1610)
- Si Saowaphak or Sanphet IV (died 1620)
- Prasat Thong or Sanphet V (died 1656)
- Chai (king of Ayutthaya) or Sanphet VI (died 1656)
- Si Suthammaracha or Sanphet VII (died 1656)
- Suriyenthrathibodi or Sanphet VIII (died 1709)
- Thai Sa or Sanphet IX (died 1733)
- Places in the Ayutthaya Historical Park
- Wat Phra Si Sanphet, an ancient Buddhist temple
- Phra Si Sanphet, a renowned Buddhist image
- Sanphet Prasat, a royal hall
- Wat Phra Si Sanphet, an ancient Buddhist temple