Living will refers to a will prepared by a person with a terminal illness, requesting that extraordinary life-sustaining procedures not be used in the event that the person's ability to make this decision is lost. Living will, moreover is a document instructing physicians, relatives, or others to refrain from the use of extraordinary measures, such as life support equipment, to prolong one's life in the event of a terminal illness.

Living wills are a form of advance directives originally intended to refuse certain cure-oriented interventions that are no longer desired by an individual; living wills usually asked that dying be permitted to take its own natural course and that suffering associated with life-threatening illness be mitigated with effective palliative care.