Depression is closely related to individual social functions. The current study aimed to examine whether depression is associated with ostracism, whether interpretation bias mediates this relationship, and whether trait mindfulness moderates direct and indirect relationships between depression and ostracism. Overall, 389 Chinese college students completed the Center for Epidemiological Survey, Depression Scale, Interpretation Bias Questionnaire, Philadelphia mindfulness scale, and perceived ostracism scale at two-time points. Latent Profile analysis and moderated mediation analysis were performed. After controlling for sex and age, depression (t1) was positively correlated to perceived ostracism, with this relationship being partially mediated by negative interpretation bias (IBN, t2). The effect of IBN on perceived ostracism was weak when awareness was high at time 2. Acceptance had a non-significant moderating role in the relationship between IBN and perceived ostracism at time 2. LPA delineated three profiles: high awareness, high acceptance, and medium mindfulness. The moderating role of the different profiles in the relationship between IBN (t2) and perceived ostracism (t2) was significant. Depressed individuals appear to experience more ostracism because of IBN. Awareness might alleviate the effect of IBN on perceived ostracism.