Child support is defined in many countries as the ongoing obligation of a non-custodial parent to a custodial parent, guardian, or caregiver to make payment for the support of children who are the result of a relationship or marriage that has broken down. The conditions for child support are often settled as a part of the arrangements of a divorce, dissolution, annulment, or marital separation of a civil union. It may also be arranged as a supplement or in addition to alimony or spousal support.

Child support is established regardless of the child being born within the confines of a marriage. Paternity or maternity has to be established for a child support obligation to be enforced by a competent court.

The idea of child support is founded on the policy that biological parents have the obligation to support their children, even when the children are not living with both parents. Child support is basically a proportion of the costs involved in raising the child. Financial support for a child by a non-custodial parent remains an obligation even when the other parent has been restricted legally from participating in the upbringing or in making decisions for the welfare of the child. In some jurisdictions, however, child support is typically tied to visitation rights of a non-custodial parent. Should the custodial parent refuse to give the other parent visitation rights, the non-custodial parent may ask the court to stop support payments temporarily. The non-custodial parent may also petition the court for additional visitation rights.

In some cases, the court allows the financial arrangements to be settled by both parents; however, in other cases, the court involves the state in the collection of financial support for the child in order to ensure a continuity of the child support payments. Also, in cases wherein the state is not involved in the collection of the payments, the non-custodial parent may petition for the court to order an accounting of the child's expenses in order to ensure that the payments are solely being used for the support of the child.