A mental health consumer is a person who is under treatment for a psychiatric illness or disorder. The term was coined in an attempt to empower those with mental health issues, usually considered a marginalized segment of society. The term suggests that those individuals have a choice in their treatment and that without them there could not exist mental health providers.

A similar definition would be a person who receives psychological services, perhaps from a psychologist, a psychiatrist or a social worker. It is an impersonal term often used in the health sector of a large economy. The consumer often expects to have some influence on service delivery and provides feedback to the provider. In Australia, the USA and other countries, informal movements driven by consumers began during the 1990s. These groups aimed to correct perceived problems in mental health services and to promote consultation with consumers. Consumer theory was devised to interpret the special relationship between a service provider and service user in the context of mental health. Consumer theory examines the consequences and sociological meaning of the relationship.