Objectives: This paper aims to examine the mediating effects of acculturative stress and loneliness when familial supports affects the happiness and depression levels of marriage-based female migrants. Method: This paper involved 316 marriage-based female migrants from five East Asian countries and was conducted from November 15, 2018 to January 30, 2019 using purposeful convenience sampling. Results: The results of structural equation modeling yielded several findings: (1) a significant direct effect on happiness and depression levels of marriage-based female migrants based on support from spouses was found, (2) the support of the spouse only had a significant mediating effect with respect to loneliness on the happiness and depression levels of marriage-based female migrants, and (3) only when the support of their children affected the happiness and depression levels of marriage-based female migrants did acculturative stress showed an indirect effect. However, no significant mediating effects were noted. Conclusions: The paper suggests that familial support, especially spousal support, was important in the process of adapting to Korean life among marriage-based female migrants.