Exercise and mental stimulation may improve cognition, physical function, and well-being of people with dementia (PWD) and older adults more generally. This study evaluated changes in physical function, physical activity, exercise self-efficacy, and mental well-being with participation in Minds in Motion®, a weekly exercise and mental stimulation program for PWD (n = 343) and care partners (n = 318). Most physical function measures improved among PWD and care partners (endurance, upper and lower body strength, upper body flexibility; ps ≤ .009). Participants also reported a significant increase in weekly frequency, duration, and intensity of physical activity (ps < .001) and in mental well-being (p < .001). Exercise self-efficacy did not change (p = .16). These results suggest that Minds in Motion® yields improvements in physical function, which may translate into better functional abilities for PWD and improved ability for their partners to care for people living with dementia.