The purpose of this study was to analyze the effects of stress perception and social support on subjective well-being according to differing levels of optimism. The participants in this study were 230 pre-service early childhood teachers, majoring in early childhood education at two universities located in Daegu, Gyeongbuk province. The results of this study could be summarized as follows. First, pre-service early childhood teachers were shown to be more optimistic, be more satisfied with life, and had higher positive emotion rates than average. They also showed lower stress perception and negative emotion rates than average. Second, the highly optimistic group showed higher levels than the less optimistic group in terms of both satisfaction with life and positive emotions. Third, the stress perception in both the highly optimistic group and the less optimistic group had an impact on their satisfaction with life, positive emotions, and negative emotions. The degree of peer support perceived by the highly optimistic group showed an impact on satisfaction with life and negative emotions, whereas the degree of parental support perceived by the less optimistic group showed an impact on their levels of satisfaction with life.