Risperidone (/rɨˈspɛərɨdoʊn/ ri-SPAIR-i-dohn) (Risperdal, and generics) is a second-generation or atypical antipsychotic. It is used to treat schizophrenia (including adolescent schizophrenia), schizoaffective disorder, the mixed and manic states associated with bipolar disorder, and irritability in people with autism. It is associated with significant weight gain and metabolic problems, as well as tardive dyskinesia and neuroleptic malignant syndrome. Risperidone and other antipsychotics also increase the risk of death in patients with dementia. The drug was developed by Janssen-Cilag and first released in 1994.

Risperidone is used for the treatment of schizophrenia, bipolar disorder, and behavior problems in people with autism. In autism, however, it does not improve conversational ability or social skills, and does not appear to reduce obsessive behavior in most autistic people.