This study tested hypotheses that people with higher social comparison orientation would have lower subjective well-being and that the relationship between social comparison orientation and subjective well-being would be mediated by materialism. Moreover, we examined whether the effect of social comparison orientation on subjective well-being through materialism tendency might depend on the level of cultural self-construal (independent self, interdependent self). We recruited 294 participants, measured their social comparison orientation, materialism tendency, subjective well-being, independent self, and interdependent self, and analyzed the mediation effect of materialism moderated by cultural self-construal on the relationship between social comparison orientation and subjective well-being. As a result, there were differences in subjective well-being depending on social comparison orientation. The relationship between social comparison orientation and subjective well-being was mediated by materialism tendency. Specifically, participants with higher social comparison orientation had a higher tendency of materialism. Such higher materialism tendency led to lower subjective well-being. However, the mediation effect of materialism tendency moderated by cultural self-construal was not statistically significant. These results showed that regardless of the level of independent or interdependent self, people with higher social comparison orientation were related to higher materialism tendency, which led to lower subjective well-being.