In medicine, specifically in end-of-life care, palliative sedation (also known as terminal sedation, continuous deep sedation, or sedation for intractable distress of a dying patient) is the palliative practice of relieving distress in a terminally ill person in the last hours or days of a dying person's life, usually by means of a continuous intravenous or subcutaneous infusion of a sedative drug, or by means of a specialized catheter designed to provide comfortable and discreet administration of ongoing medications via the rectal route.

As of 2013, approximately tens of millions of people a year were unable to resolve their needs of physical, psychological, or spiritual suffering at their time of death. Due to the amount of pain a dying person may face, palliative care is considered important. Proponents claim palliative sedation can provide a more peaceful and ethical solution for such people.

Palliative sedation is an option of last resort for the people whose symptoms cannot be controlled by any other means. It is not considered a form of euthanasia or physician-assisted suicide, as the goal of palliative sedation is to control symptoms, rather than to shorten or end the person's life.

Palliative sedation is legal everywhere and has been administered since the hospice care movement began in the 1960s. The practice of palliative sedation has been a topic of debate and controversy as many view it as a form of slow euthanasia or mercy killing, associated with many ethical questions.^{[citation needed]} Discussion of this practice occurs in medical literature, but there is no consensus because of unclear definitions and guidelines, with many differences in practice across the world.

Palliative sedation is the use of sedative medications to relieve refractory symptoms when all other interventions have failed. The phrase "terminal sedation" was initially used to describe the practice of sedation at end of life, but was changed due to ambiguity as to what the word 'terminal' meant. The term "palliative sedation" was then used to emphasize palliative care. The level of sedation via palliative sedation may be mild, intermediate or deep and the medications may be administered intermittently or continuously.

The term "refractory symptoms" is defined as symptoms that cannot be controlled despite the use of extensive therapeutic resources, with such symptoms having an intolerable effect on the patient's well-being in the final stages of life. The symptoms may be physical, psychological, or both.

Palliative care is aimed to relieve suffering and improve the quality of life for people with serious and/or life-threatening illness in all stages of disease, as well as for their families. It can be provided either as an add-on therapy to the primary curative treatment or as a monotherapy for people who are on end-of-life care. In general, palliative care focuses on managing symptoms, including but not limited to pain, insomnia, mental alterations, fatigue, difficulty breathing, and eating disorders. In order to initiate the care, self-reported information is considered the primary data to assess the symptoms along with other physical examinations and laboratory tests. However, in people at the advanced stage of the disease with potential experience of physical fatigue, mental confusion or delirium which prevent them from fully cooperating with the care team, a comprehensive symptom assessment can be utilized to fully capture all symptoms as well as their severity.

There are multiple interventions that can be used to manage the conditions depending on the frequency and severity of the symptoms, including using medications (i.e. opioid in cancer-related pain), physical therapy/modification (i.e. frequent oral hygiene for xerostomia/dry mouth treatment), or reversal of precipitating causes (i.e. low fiber diet or dehydration in constipation management).