A posthumous birth is a birth of a child after the death of a parent.

A posthumous birth has special significance in the case of hereditary monarchies following primogeniture.

Posthumous birth has special implications in law, potentially affecting the child's citizenship and legal rights, inheritance, and order of succession.

The crowd went silent, and soon a body the size of a doll came out, what one doctor called a posthumous birth from a pregnant mother in the trailer.

Because of his posthumous birth when the senior line of the Bourbon dynasty appeared about to become extinct, he was given the name Dieudonné ("God-given", in English).

Most instances of posthumous birth involve the birth of a child after the death of its father, but the term also is applied to infants delivered after the death of the mother, usually by caesarean section.

Black's Law Dictionary defines the rule against perpetuities as "[t]he common-law rule prohibiting a grant of an estate unless the interest must vest, if at all, no later than 21 years (plus a period of gestation to cover a posthumous birth) after the death of some person alive when the interest was created."