Alcohol intoxication (also known as drunkenness among other names) is a physiological state (that may also include psychological alterations of consciousness) induced by the ingestion of ethanol (alcohol).

Alcohol intoxication is the result of alcohol entering the bloodstream faster than it can be metabolized by the liver, which breaks down the ethanol into non-intoxicating byproducts. Some effects of alcohol intoxication (such as euphoria and lowered social inhibitions) are central to alcohol's desirability as a beverage and its history as one of the world's most widespread recreational drugs. Despite this widespread use and alcohol's legality in most countries, many medical sources tend to describe any level of alcohol intoxication as a form of poisoning due to ethanol's damaging effects on the body in large doses. Some religions consider alcohol intoxication to be a sin.

Symptoms of alcohol intoxication include euphoria, flushed skin, and decreased social inhibition at lower doses, with larger doses producing progressively severe impairments of balance, muscle coordination (ataxia), and decision-making ability (potentially leading to violent or erratic behavior) as well as nausea or vomiting from alcohol's disruptive effect on the semicircular canals of the inner ear and chemical irritation of the gastric mucosa. Sufficiently high levels of blood-borne alcohol will cause coma and death from the depressive effects of alcohol upon the central nervous system.