The aim of the current study was to investigate whether optimism and self-efficacy mediated the association between shyness and subjective well-being in a sample of Chinese working adults. Two hundred and eight participants completed the Revised Cheek and Buss Shyness Scale, Life Orientation Rest-Revised, Satisfaction with Life Scale, and Positive and Negative Affect Scale. Structural equation modeling results showed that optimism mediated the relationship between shyness and measures of subjective well-being (life satisfaction, positive and negative affect). Self-efficacy mediated the association between shyness and positive subjective well-being (life satisfaction and positive affect). These results suggest that optimism and self-efficacy play unique moderating roles in the relationship between shyness and subjective well-being. They also have important implications for the development of intervention programs aimed at promoting subjective well-being through enhancing self-efficacy and optimism.