Objective: To comprehensively evaluate the psychometric properties of the relatively new Everyday Ageism Scale. Methods: Data were from the 2021–2023 Experiences of Aging in Society project (N = 237, ages 50+, multiracial/multiethnic, 72.6% female). We assessed the multidimensional structure, reliability, and validity of the Everyday Ageism Scale. Results: Confirmatory factor analysis generally substantiated the three-factor structure of the Everyday Ageism Scale: exposure to ageist messages, ageism in interpersonal interactions, and internalized ageism. Internal consistency and test-retest reliability were satisfactory for the full scale and two of the three subscales. The scale demonstrated acceptable validity for convergence within measure, convergence criterion with three other scales used to measure ageism, and prediction of concurrent health (number of chronic physical health conditions, mental health condition). Discussion: Findings establish the Everyday Ageism Scale as a valid and reliable, multidimensional scale, while recommending ongoing attention to messages subscale limitations.