An analgesic or painkiller is any member of the group of drugs used to achieve analgesia, relief from pain.

Analgesics act in various ways on the peripheral and central nervous systems — distinct from anesthetics, which temporarily affect, and in some instances completely eliminate, sensation.

Analgesics include acetaminophen, the nonsteroidal anti-inflammatory drugs (NSAIDs) such as the salicylates, and opioid drugs (not included here) such as morphine and oxycodone.