Older adults make up a significant and increasing proportion of the U.S. population and are frequent users of healthcare services. Ageism in healthcare, driven by an incomplete and narrowly biomedical perspective on aging, has been linked to various problematic outcomes for older patients, including under- and over-treatment. The purpose of this study was to use the theory of relational ageism to explore the relationship between personal aging anxiety among healthcare professionals and their attitudes to older patients, considering the potentially moderating factors of job role and work setting. Using convenience sampling, clinical healthcare professionals working for a mid-sized, regional healthcare system in the Mid-Atlantic region of the United States were invited to participate in an online survey, resulting in a sample of N = 145. Independent variables in this study included the sociodemographic variables of gender, age, race, ethnicity, level of education, formal geriatric or gerontological education, and years of expression, plus job role, work setting, and aging anxiety scores as measured by the Aging Anxiety Scale. The dependent variable was attitudes to older patients as measured by the Geriatric Attitudes Scale. Regression analysis findings suggest that while having formal geriatric or gerontological education was associated with more negative attitudes to older patients, other sociodemographic variables including gender, age, race, ethnicity, level of education, and years of experience were not predictive of attitudes to older patients. While physicians had more negative attitudes toward older patients than did nurses, therapists, and other types of clinicians, work setting was not predictive of attitudes toward older patients. Study findings also indicate that higher levels of personal aging anxiety of healthcare professionals were correlated with more negative attitudes to older patients. This study provides information that can inform diversity training for healthcare professionals in order to improve attitudes toward older patients and reduce age discrimination in healthcare. A key recommendation is the inclusion of an exploration of healthcare professionals’ internalized attitudes to aging in any diversity training in order to increase awareness that these internalized attitudes about aging may influence their attitudes to older patients.