Recent studies have highlighted how newcomer misfit is a critical antecedent of turnover, but the possible psychological mechanism and conditional factors in this process have not been explored. Thus, we employed a model of organizational frustration to examine whether subordinates' organizational frustration mediates the relationship between newcomers' person-job (P–J) misfit and turnover intention. Moreover, we investigated the moderated mediation effect of authoritarian leadership on the above relationship, finding that P–J misfit includes the need-supply (N‒S) and demand-ability (D–A) misfits. In sample 1, the data were collected from 302 military newcomers; in sample 2, the data were collected from 163 policeman and firefighter newcomers. These two samples were collected at two different time points and with different units. Our study results are therefore as follows: (1) In samples 1 and 2, organizational frustration positively mediated the relationship between newcomers' N‒S misfit/D–A misfit and turnover intention; (2) in sample 1, authoritarian leadership strengthened the relationship between newcomers' D–A misfit and organizational frustration; thus, turnover increased. However, in sample 2, authoritarian leadership could not strengthen the relationship between newcomers' N‒S misfit/D–A misfit and organizational frustration. Finally, we also discuss the theoretical and practical implications of our results.