Animal euthanasia (from ) is the act of killing an animal humanely, most commonly with injectable drugs. Euthanasia methods are designed to cause minimal pain and distress. Animal euthanasia is distinct from animal slaughter.

Euthanasia is often used in the following cases: to end an animal's suffering from terminal, incurable (and especially painful) conditions or diseases, when there is a lack of resources to continue supporting the animal, or at the end of laboratory test procedures.