Child custody (also known as legal custody, conservatorship, or allocation of parenting time and responsibilities) refers to the legal possession, rights, and responsibilities for a minor child by the child’s birth or adoptive parents—including the right to make health care, religious, cultural, and education decisions about the child's upbringing.

During separation, and following divorce, a child’s natural parents often share custody of the child (shared custody or joint custody)—unless one or both of the child’s natural or adoptive parents are deemed to be unfit or pose a risk to the health, safety, and well-being of the child (the child’s best interests). If one of the parents is deemed unfit, the other parent may be awarded sole custody of the child. In some cases a parent who is not allowed to have custody of a child may be given visitation rights—sometimes under the supervision of another adult (supervised visitation). Child custody laws are usually located in your state’s statutes governing family and domestic matters, and may be referred to as the Family Code.

Child custody is distinct from guardianship of a child, which usually involves a relative or an unrelated person temporarily agreeing to take responsibility for a child following the death of the child’s birth or adoptive parents, or their abandonment. And adoption is taking full and permanent responsibility for a child by someone other than the child’s birth parents.

In Illinois, child custody is legally referred to as the allocation of parental responsibilities, which includes both parenting time and decision-making authority regarding the child's upbringing. Illinois law prioritizes the best interests of the child when determining custody arrangements during separation or divorce. Parents may be granted joint custody, which involves shared decision-making and parenting time, or sole custody if one parent is deemed unfit or poses a risk to the child's well-being. Unfit parents may be denied custody but could be granted visitation rights, which may require supervision in certain cases. The Illinois Marriage and Dissolution of Marriage Act (750 ILCS 5/) governs child custody matters and outlines the factors considered by courts in making custody determinations. These factors include the wishes of the child and parents, the child's adjustment to home, school, and community, the mental and physical health of all individuals involved, and any history of violence or threat of violence by the child's potential custodian. Guardianship and adoption are separate legal arrangements from child custody, with guardianship often being a temporary arrangement and adoption being a permanent legal responsibility for a child by individuals other than the birth parents.