Haloperidol is a typical antipsychotic. It is in the butyrophenone class of antipsychotic medications and has pharmacological effects similar to the phenothiazines.

Haloperidol is an older antipsychotic used in the treatment of schizophrenia and acute psychotic states and delirium. A long-acting decanoate ester is used as an injection given every four weeks to people with schizophrenia or related illnesses who have a poor compliance with medication and suffer frequent relapses of illness, or to overcome the drawbacks inherent to its orally administered counterpart that burst dosage increases risk or intensity of side effects. In some countries, injections of antipsychotics such as haloperidol can be ordered by a court at the request of a psychiatrist.

Haloperidol is sold under the tradenames Aloperidin, Bioperidolo, Brotopon, Dozic, Duraperidol (Germany), Einalon S, Eukystol, Haldol, Halosten, Keselan, Linton, Peluces, Serenace, Serenase, and Sigaperidol.

Haloperidol was discovered by Paul Janssen. It was developed in 1958 at the Belgian company Janssen Pharmaceutica and submitted to the first of clinical trials in Belgium later that year.