While job identity is significantly related to personality traits and adaptation to the work environment, few studies have focused on job identity profile or on its relationships with the characteristics of young adults. This study aimed to identify the identity profiles of young workers in Japan and examine their associations with these employees’ personality traits, job satisfaction, work engagement, and emotional impairment. The survey participants were 500 working Japanese young adults (46.6% female; Mage = 26.12, SD = 2.34). The results of the latent profile analysis identified four job identity profiles: achievement, closure, moratorium, and diffusion. The results of the Chi-square test indicated that young adults in part-time employment were more likely to be classified under the moratorium profile than full-time workers. The results of the multivariate analysis of variance indicated that young adults with high commitment profiles (i.e., the achievement and closure profiles) had higher job satisfaction and work engagement than those with low commitment profiles (i.e., the moratorium and diffusion profiles). Future research directions and managerial implications were finally discussed.