A delusion of grandeur is a false or unusual belief about one’s power, wealth, talents, and other traits. A person may believe, for instance, that they are famous, can end world wars, or that they are immortal.

Delusions of grandeur, also called grandiose delusions, often accompany other mental health symptoms, including other delusions. The may be related to mental or physical health conditions, including schizophrenia, bipolar disorder, or some types of dementia.