Guardian, in law, a person or institution entrusted with the care of another person (called a ward), or another's property, or both person and property. A guardian acts for a person who is incapable of managing his own affairs. A ward may be a minor or a mentally ill, mentally retarded, or senile person.

When a minor has no parent to provide care, the child must have a guardian, who may be named in the will of the deceased parent or appointed by a court. In the case of an incompetent adult, the court selects a guardian, usually a relative. The guardian must provide for the ward's needs out of the funds derived from the property; he is not required to support the ward at his own expense. He is also empowered to direct the education of a minor ward. The guardian must exercise prudence in his care of the property and must give an accounting periodically and at the end of the guardianship.

The guardian may be compensated subject to court approval, but must not otherwise enrich himself out of the property. The guardian may be removed by the court for improper management of the property.