Ageism is a critical global problem that is defined as negative attitudes and behaviors toward older individuals, including stereotyping, prejudice, and discrimination. The aim of this review article was to elucidate how ageism affects the health quality of older individuals and the interventional strategies developed to combat ageism. Previous studies have highlighted the adverse effects of ageism on health quality among 11 health domains, including denied access to health care and treatment, lack of employment opportunities, mental illness, physical illness, exclusion from health research, and poor quality of life and well-being. The previous studies revealed that among health professionals and older individuals, ageism was associated with negative effects on medical decision-making and communication. Moreover, interventional strategies developed to combat ageism involved the use of positive education and contact experience models, empathy simulation training, and evidence-based research to bridge gaps in practice. In conclusion, ageism is a common phenomenon in society and health care systems and among older individuals and health care professionals. Ageism problems must be resolved and the health quality of older individuals must be improved through intergenerational understanding and through interprofessional teamwork in educational training and research.