This paper summarizes the prevalence, impact, and presentation of ageism across multiple mental health care settings including inpatient, outpatient, long-term care, and criminal justice. Strategies for combating ageism are described. Ageism is a common form of bias that has deleterious medical and psychosocial consequences for older adults. Ageism manifests in a variety of ways in mental health settings. Clinical, educational, and public policy strategies are recommended to combat ageism in mental health settings. Ageism remains pervasive in society and in mental health care settings. Ageism impacts healthcare trainees, healthcare providers, healthcare systems, and older adults themselves. Age-friendly practices and strategies for combating ageism exist and need broader dissemination.