Incest is illegal in several important circumstances in Ohio, but Ohio does not have a single criminal statute that bans every sexual relationship between all close relatives. Instead, the state’s sexual-battery law specifically criminalizes sexual activity involving certain family and parental relationships, while separate marriage laws prohibit close relatives from marrying.
Ohio Revised Code Section 2907.03 makes sexual activity illegal when one person is the other’s natural or adoptive parent, stepparent, guardian, custodian or person acting in loco parentis. Importantly, this restriction can apply even when both people are adults and the sexual activity is claimed to be consensual.
The exact family relationship therefore matters when determining whether conduct constitutes a crime under Ohio law.
Does Ohio Have an Incest Law?
Ohio does not currently have a separate criminal offense simply titled “incest” in Chapter 2907 of the Ohio Revised Code.
Instead, the principal criminal provision covering incestuous parent-child relationships is Ohio Revised Code Section 2907.03(A)(5), part of the state’s sexual-battery law.
It prohibits sexual activity when the offender is the other person’s:
- Natural parent
- Adoptive parent
- Stepparent
- Guardian
- Custodian
- Person acting in loco parentis
The Ohio Supreme Court has itself referred to Section 2907.03(A)(5) as Ohio’s incest statute when interpreting the provision.
Is Sex Between a Parent and Adult Child Illegal in Ohio?
Yes.
Ohio’s law does not contain an exception simply because the child has reached adulthood or says the relationship was consensual.
Section 2907.03(A)(5) applies when the offender is the other person’s natural or adoptive parent. The statute does not restrict that provision to minor children.
Ohio courts have applied the law to adult family relationships.
In State v. Freeman, for example, a case involved a father charged under Section 2907.03(A)(5) in connection with his 20-year-old daughter.
Therefore, adulthood and consent do not make sexual activity between a parent and child lawful under this provision.
Is Sex Between a Stepparent and Adult Stepchild Illegal?
Yes, while the legal stepparent-stepchild relationship exists.
The Ohio Supreme Court directly addressed this issue in State v. Lowe. The case involved consensual sexual activity between a stepparent and his 22-year-old stepdaughter.
The court ruled that Section 2907.03(A)(5) applies regardless of the stepchild’s age or consent and upheld the law as constitutional.
However, there is an unusual limitation.
Ohio courts have held that if the marriage creating the stepparent relationship ends, the stepparent-stepchild relationship can also terminate for purposes of this particular statute. A 2024 Ohio appellate decision reversed a sexual-battery conviction where the defendant’s marriage to the alleged victim’s mother had ended years before the conduct occurred.
That does not mean other sexual-offense laws could not apply depending on the circumstances.
What About Consensual Sex Between Adult Siblings?
Ohio’s criminal statute is narrower here than many people expect.
Section 2907.03(A)(5) specifically lists parents, adoptive parents, stepparents, guardians, custodians and people acting in loco parentis. It does not expressly list brothers, sisters, first cousins, aunts, uncles, nieces or nephews solely because they are relatives.
Therefore, consensual sexual activity between two competent adult siblings is not expressly criminalized by Section 2907.03(A)(5) merely because they are siblings.
That should not be interpreted as a general statement that every situation involving adult relatives is lawful. Other criminal laws can apply if there is:
- Force or coercion
- Lack of consent
- Substantial impairment
- A minor involved
- A prohibited authority or custodial relationship
- Other circumstances covered by Ohio’s sex-offense laws
Ohio institutions may also have policies defining incest more broadly for Title IX or campus disciplinary purposes. Those policies should not be confused with the scope of the state criminal statute.
Can Close Relatives Get Married in Ohio?
Ohio separately restricts marriage between close relatives.
Ohio Revised Code Section 3101.01 states that people who are nearer of kin than second cousins may not marry.
In practical terms, this prevents marriages involving relationships such as:
- Parent and child
- Grandparent and grandchild
- Brothers and sisters
- Aunt or uncle and niece or nephew
- First cousins
Second cousins are not within the prohibited degree described by the statute.
This marriage restriction is separate from the criminal sexual-battery provision. A family relationship can therefore be prohibited for marriage even when that particular relationship is not expressly listed in Section 2907.03(A)(5).
What If a Minor Is Involved?
The legal consequences become significantly more serious when sexual activity involves a minor.
Ohio’s general sex-offense laws apply regardless of whether the parties are related.
For example, Ohio law provides that sexual conduct with a person under 13 can constitute rape regardless of whether the offender knew the child’s age.
Ohio Revised Code Section 2907.04 also prohibits an adult age 18 or older from engaging in sexual conduct with someone who is 13, 14 or 15 when the adult knows or is reckless regarding the minor’s age.
The parent, stepparent or guardian provision of the sexual-battery law provides an additional basis for prosecution when that relationship exists.
What Are the Penalties for Incest-Related Sexual Battery?
The penalty depends partly on the type of sexual activity and the age of the other person.
Under the current version of Section 2907.03:
- Sexual battery involving sexual conduct is generally a third-degree felony
- If the other person is between 13 and 17, sexual battery involving sexual conduct is generally a second-degree felony with a mandatory prison term
- Sexual battery involving sexual contact is generally a fifth-degree felony
- Sexual contact involving someone under 18 generally raises the offense to a fourth-degree felony
For a third-degree felony sexual-battery conviction covered by Ohio’s sentencing statute, available prison terms can range from 12 to 60 months, depending on sentencing circumstances.
More serious charges, including rape, can carry substantially greater penalties.
Does an Incest-Related Conviction Require Sex-Offender Registration?
A sexual-battery conviction can trigger Ohio’s sex-offender registration system.
Under Ohio law, sexual battery involving sexual conduct is generally classified as a Tier III sexually oriented offense, while sexual battery involving sexual contact generally falls under Tier II.
For adult offenders, Tier III registration obligations generally continue for life, while Tier II registration generally continues for 25 years.
This means the consequences of a conviction can extend far beyond the initial criminal sentence.
Is Consent a Defense to Parent-Child Incest in Ohio?
Not under Section 2907.03(A)(5).
The statute is based on the prohibited relationship itself. It does not require prosecutors to prove that an adult child did not consent when the accused is the person’s natural parent, adoptive parent, qualifying stepparent, guardian, custodian or person acting in loco parentis.
The Ohio Supreme Court confirmed this principle in State v. Lowe, holding that the prohibition could constitutionally apply even to consensual sexual activity between an adult and a stepparent.
Final Word
Incest is not broadly legal in Ohio in 2026. Ohio criminalizes sexual activity between a person and their natural or adoptive parent, qualifying stepparent, guardian, custodian or person acting in loco parentis, even when the other person is an adult and claims to consent.
However, Ohio’s criminal law does not create a blanket incest offense covering every category of adult relative. For example, siblings are not specifically included in Section 2907.03(A)(5) solely because of their sibling relationship.
Ohio’s marriage rules are broader: people nearer in kinship than second cousins cannot legally marry. When minors, force, lack of consent or other prohibited circumstances are involved, additional and often much more serious sex-offense laws apply.