Usul (disambiguation)

Usul (Arabic: أصول, lit. principles) may refer to:

• Usul al-Fiqh (traditional methodological principles used in fiqh for deriving the rulings of Islamic law)
• Al-Usul al-Arba'a (the four works of hadith regarded as reliable by the Shi'as)
• Usul al-Din (a set of essential beliefs in Islam that every Muslim needs to believe in)
• Usul al-kafi, the work of al-Kulayni
• Al-Usul al-arba'ami'a (four hundred hadith collections which were collected by the transmitters of hadith directly from the Prophet (s) and Imams (a) in the early centuries of Islam)