In the law of property, a pretermitted heir is a person who would likely stand to inherit under a will, except that the testator (the person who wrote the will) did not include the person in the testator's will. Omission may occur because the testator did not know of the omitted person at the time the will was written.

A will may contain a clause that explicitly disinherits any heirs unknown at the time that the will is executed, or any heirs not named in the will. While such a clause will not necessarily prevent a claim against an estate by a pretermitted heir, it may make it more difficult to succeed in such an action.

Forced heirship is a form of testate partible inheritance whereby the estate of a deceased is separated into (1) an indefeasible portion, the forced, passing to the deceased's next-of-kin, and (2) a discretionary portion, or free estate, to be freely disposed of by will. Forced heirship is generally a feature of civil-law legal systems which do not recognize total freedom of testation. Normally, the deceased's estate is in-gathered and wound up without discharging liabilities, which means accepting inheritance includes accepting the liabilities attached to inherited property. The forced estate is divided into shares which include the share of issue (legitime or child's share) and the spousal share. This provides a minimum protection that cannot be defeated by will. The free estate, on the other hand, is at the discretion of a testator to be distributed by will on death to whomever he or she chooses. Takers in the forced estate are known as forced heirs.

The expression comes from Louisianan legal language and is ultimately a calque of Spanish sucesión forzosa.