Reducing loneliness and enhancing subjective well-being are key topics in psychological research. However, few studies have explored the impact of cultural factors on loneliness and subjective well-being from a cultural perspective. Moreover, there has been few research examining the underlying mechanisms through which sociocultural factors influence individual loneliness and well-being. This study aims to explore the influence of a personality trait rooted in Chinese Confucian culture-Junzi personality-on subjective well-being among Chinese, specifically examining the mediating roles of self-reflection and self-control. A sample of 693 Chinese college students were surveyed on their Junzi personality, self-reflection, self-control, loneliness, and subjective well-being in three stages over 6 months. Correlation analysis and a multiple mediation model were conducted using SPSS 23.0 and AMOS 23.0. Results revealed that Junzi personality positively predicted subjective well-being and negatively predicted loneliness. Additionally, self-reflection, self-control, and loneliness sequentially mediated the effect of Junzi personality on subjective well-being. This study highlights the significant role of cognitive factors in the process through which sociocultural factors influence well-being.