Subinfeudation, in English law, the practice by which tenants, holding land under the king or other superior lord, carved out in their turn by sub-letting or alienating a part of their lands new and distinct tenures.

The tenants were termed "mesne-lords," with regard to those holding from them, the immediate tenant being tenant in capite. The lowest tenant of all was the freeholder, or, as he was sometimes termed tenant paravail. The Crown, who in theory owned all lands, was lord paramount.

The great lords looked with dissatisfaction on the increase of such subtenures. Accordingly in 1290 a statute was passed, Quia Emptores, which allowed the tenant to alienate whenever he pleased, but the alienee or person to whom he granted was to hold the land not of the alienor but of the same immediate lord, and by the same services as the alienor held it before.