Physical activity (PA) among older adults is understudied in middle-income countries. The authors examined the associations of factors across levels of the social ecological model (individual, interpersonal, organizational, and community) with older adults meeting guidelines of 150 min of moderate- to vigorous-intensity PA per week through walking in three middle-income countries: Albania (n = 387), Colombia (n = 404), and Brazil (n = 402). Using 2012 International Mobility in Aging Study data, multivariate logistic regression models identified the following significant associations with meeting PA guidelines through walking (a) individual level: depression (odds ratio [OR] = 0.62, 95% confidence interval, CI [0.45, 0.86]), being female (OR = 0.74, 95% CI [0.56, 0.998]), and high relative education (OR = 1.79, 95% CI [1.33, 2.41]) and (b) interpersonal level: high life partner (OR = 1.38, 95% CI [1.04, 1.83]) and friend social ties (OR = 1.39, 95% CI [1.05, 1.83]). While individual and interpersonal variables were associated with meeting PA guidelines, community-level social and environmental variables were not.