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 Colorado, the 'best interests of the child' standard is the guiding principle for courts when making decisions regarding child custody and visitation rights. This standard is codified in Colorado Revised Statutes Section 14-10-124. The statute outlines several factors that courts must consider to determine what arrangement will best serve the child's needs. These factors include the child's wishes, the child's relationship with each parent, the child's adjustment to home, school, and community, the mental and physical health of all individuals involved, the ability of the parents to encourage the sharing of love and affection, and any history of child abuse or domestic violence. Colorado law does indeed presume that it is beneficial for the child to maintain a relationship with both parents unless evidence suggests that a parent is unfit due to reasons such as abuse, neglect, or substance abuse. The court's primary focus is always on the child's safety, well-being, and overall best interests rather than the parents' desires or convenience.