An heiress is a female beneficiary expected to receive, or who has received, a substantial inheritance from a deceased person’s estate, typically in a family succession context. In modern UK and Irish law, “heiress” is not a technical term and is rarely used in legislation or formal legal drafting, which instead refers to “beneficiaries”, “heirs”, “successors” or “persons entitled” under a will or on intestacy.The expression is mainly descriptive and encountered in client communications, older deeds or settlements, trust instruments, family constitutions, and media reporting on family wealth. It may indicate entitlement under a will, under intestacy rules, or under discretionary or fixed trusts, but carries no special legal status or priority merely by virtue of gender.Across England and Wales, Scotland, Northern Ireland and Ireland, usage is broadly consistent. Succession and inheritance rights are governed by the relevant succession, intestacy and trust legislation, and by case law, which are gender‑neutral. Where historic instruments refer to an “heiress” or “heiress of the body”, interpretation will follow standard principles of construction, giving effect to the settlor’s or testator’s intention and the governing statutory framework.