Nurses, as healthcare professionals who frequently interact with older patients in clinical settings, play a crucial role in providing direct care and services to older patients. However, nurses caring for older patients often experience substantial physical and emotional exhaustion, which can trigger a loss of motivation, feelings of helplessness, and burnout. The current study, conducted in Korea, investigated the impact of ageism on burnout among clinical nurses. To determine whether ageism was a significant predictor of nurse burnout, a structured questionnaire was distributed to 332 nurses at two hospitals. Multiple regression analysis then showed that ageism (B = .066, p < .001), female sex (B = .530, p = .003), and lower preference for geriatric nursing (B = .357, p = .002) were significantly associated with burnout. Our findings confirmed that ageism was strongly associated with nurse burnout, suggesting the need to develop interventions or training programs that can change nurses’ perception of older people and facilitate emotional change.