The aim of the present study was to empirically investigate the role of age‐friendly environments (AFE) on the associations between income, informal social networks, and health among South Korean older adults. We used data from the “2017 Age Integration Survey” collected nationally and ultimately analyzed 615 older adults over 50 years of age. Structural equation modeling and multi‐group analysis were used to test the hypothesis. Specifically, two groups of perceived levels of AFE (top 25%, bottom 25%) were compared in order to examine the moderating effects. The results indicated that poor income and scarce informal social networks each had a significantly adverse impact on health. However, the effect of income on health was no longer significant for older adults living in environments that were more age‐friendly. In both groups, the presence of fewer informal social networks adversely impacted health, although the sizes of the effects decreased when the level of AFE perceived by older adults was improved. Finally, several implications of the study findings were discussed.