An heir presumptive or heiress presumptive is the person provisionally scheduled to inherit a throne, peerage, or other hereditary honour, but whose position can be displaced (in legal terms, is "subject to divestiture") by the birth of an heir or heiress apparent or of a new heir presumptive with a better claim to the position in question. When lowercased, "heir presumptive" can refer generally to someone who is provisionally scheduled to inherit a title, position or possession, unless displaced by an heir apparent or another heir presumptive born further up the line of succession. In both cases, the position is however subject to law and/or conventions that may alter who is entitled to be heir presumptive.

Depending on the rules of the monarchy the heir presumptive might be the daughter of a monarch (if males take priority over females and the monarch has no sons), or the senior member of a collateral line (if the monarch is childless).

For more detailed information, and a comparison between the positions of heir presumptive and heir apparent, see heir apparent.