The best interests of the child refers to the factors most courts consider when making decisions on child custody and visitation rights.

These factors may include the needs and circumstances of the child (happiness, security, mental health, emotional development, educational opportunities, special needs, siblings, religious and cultural considerations, continuity and stability, child’s wishes) and the circumstances of the parent or caregiver (relationships, living arrangements, history of abuse, mental health, physical health, financial resources, substance abuse).

There is generally a presumption that it is in a child’s best interests to have a relationship with both of the child’s biological parents—unless one or both of the parents are shown to be unfit parents.

In Idaho, the 'best interests of the child' standard is the guiding principle for courts when making decisions regarding child custody and visitation rights. Idaho Code § 32-717 provides the legal framework for determining child custody arrangements. The statute outlines several factors that courts must consider to ascertain what will best serve the child's welfare and happiness. These factors include the wishes of the child's parent(s), the child's wishes, the relationship between the child and each parent, the child's adjustment to home, school, and community, the character and circumstances of all individuals involved, and the need to promote continuity and stability in the life of the child. Additionally, the court will consider the mental and physical health of all parties involved. While there is a presumption that maintaining a relationship with both biological parents is in the child's best interest, this presumption can be overcome if evidence shows that a parent is unfit due to reasons such as abuse, neglect, or substance abuse. The court's primary focus is always on the welfare and best interests of the child over any other consideration.