Abu Bakr al-Khassaf (Arabic: أبو بكر الخصاف,Abu Bakr Al-Ḫaṣṣāf ) (died 874, full name Abu-Bakr Ahmad Ibn-Amru ash-Shaybani al-Khassaf) was a Hanafite law scholar at the court of the 14th Abbasid Caliph al-Muhtadi.
He is the author of a seminal work on Qādī, known as أدب القاضي Adab al-qādī.
Al-Ḫaṣṣāf is also the author of a Kitāb al-ḥiyal wa-l-maḫārij, a work on legalistic trickery or ḥiyal, and a kitāb aḥkām al-awqāf, on religious institutions or waqf.
The earliest development of this field is the Kitāb al-maḫārij fī l-ḥiyal ("book of evasion and trickery") by Muhammad al-Shaybani (d. 805).
A more comprehensive treatment is the Kitāb al-ḥiyal wa-l-maḫārij by Al-Khassaf.