Social distancing, a critical measure to manage COVID-19 transmission, is consistently associated with social isolation, a major health issue. Social isolation negatively impacts mental and physical health, particularly among older adults. A pre-post comparison study examined changes in cognitive function and perceived health among 36 community-dwelling Brazilian older adults, assessed pre and post social distancing measures enacted due to COVID-19. A significant increase in cognitive function was found 1 month into social distancing ( M = 16.3, p = .002, power = 0.88), with declining scores for vitality ( M = −29.3, p < .001, power = 0.99) and mental health ( M = −38.1, p < .001, power = 0.99), particularly among participants who lived alone ( t = −3.8, p = .001). Older adults exhibit rapid changes in perceived health when excluded from participation in social activities. Health care professionals should consider holistic approaches when addressing the impacts of social isolation on this population.