Oxycodone, sold under various brand names such as Roxicodone and OxyContin (which is the extended release form), is a strong, semi-synthetic opioid used medically for treatment of moderate to severe pain. It is highly addictive and a commonly abused drug. It is usually taken by mouth, and is available in immediate-release and controlled-release formulations. Onset of pain relief typically begins within fifteen minutes and lasts for up to six hours with the immediate-release formulation. In the United Kingdom, it is available by injection. Combination products are also available with paracetamol (acetaminophen), ibuprofen, naloxone, naltrexone, and aspirin.

Common side effects include euphoria, constipation, nausea, vomiting, loss of appetite, drowsiness, dizziness, itching, dry mouth, and sweating. Severe side effects may include addiction and dependence, substance abuse, irritability, depression or mania, delirium, hallucinations, hypoventilation, gastroparesis, bradycardia, and hypotension. Those allergic to codeine may also be allergic to oxycodone. Use of oxycodone in early pregnancy appears relatively safe. Opioid withdrawal may occur if rapidly stopped. Oxycodone acts by activating the μ-opioid receptor. When taken by mouth, it has roughly 1.5 times the effect of the equivalent amount of morphine.

Oxycodone was first made in Germany in 1916 from thebaine. It is on the World Health Organization's List of Essential Medicines. It is available as a generic medication. In 2020, it was the 54th most commonly prescribed medication in the United States, with more than 12 million prescriptions. A number of abuse-deterrent formulations are available, such as in combination with naloxone or naltrexone.