Incest is marriage or sexual relations between close relatives. The criminal offense of incest may also be known as prohibited sexual conduct. Laws vary from state to state, but incest laws generally prohibit marriage or sexual relations between (1) a person’s ancestor or descendant by blood or adoption; (2) a person’s current or former stepchild or stepparent; (3) a person’s parent’s brother or sister of the whole or half blood; (4) a person’s brother or sister of the whole or half blood or by adoption; (5) the children of a person’s brother or sister of the whole or half blood, or by adoption; or (6) the son or daughter of a person’s aunt or uncle of the whole or half blood or by adoption.

Lack of consent to sexual relations between such relatives is not an element of the crime, and persons may be guilty of the crime even if both parties consented.

Laws regarding incest or prohibited sexual contact vary from state to state and are generally located in a state’s statutes—often in the penal or criminal code. The crime is a felony offense in many states, with potential punishment of significant jail or prison time.

In Florida, incest is defined as marriage or sexual relations between people who are closely related by blood or adoption. Under Florida law, specifically Florida Statutes Section 826.04, it is illegal for any person to marry or engage in sexual activity with a person to whom they are related by lineal consanguinity, which includes ancestors and descendants, or with a brother, sister, uncle, aunt, nephew, or niece, whether by whole or half blood. The law applies to both natural and adopted relationships. Incest is considered a third-degree felony in Florida, and those convicted can face penalties including imprisonment, fines, or both. Consent is not a defense to the crime of incest in Florida, meaning that even if both parties agree to the sexual relationship, it is still considered a criminal offense.