Objective To evaluate the sleep quality, suicidal ideation and mental resilience of military personnel, and explore the role of mental resilience in moderating sleep quality and suicidal ideation.Methods Participants were recruited from military personnel by cluster sampling in May 2020. Pittsburgh sleep quality index (PSQI) scale, self-rating idea of suicide scale (SIOSS) and Connor-Davidson resilience scale (CD-RISC) were used to evaluate their sleep quality, suicidal ideation and mental resilience, respectively.Results A total of 13 831 questionnaires were collected, of which 10 367 were effective, with an effective rate of 74.95%. The total score of PSQI scale was 5.04±3.60, and the detection rate of poor sleep quality was 21.13% (2 191/10 367); the total score of SIOSS was 2.84±3.33, and the detection rate of suicidal ideation was 3.30% (342/10 367); and the total score of CD-RISC was 70.54±15.32. There were significant differences in sleep quality, suicidal ideation and mental resilience among officers and soldiers with different genders and education backgrounds (all P < 0.05). After controlling for sociodemographics, sleep quality (β=0.46, P < 0.01), mental resilience (β=-0.31, P < 0.01) and their interaction (β=-0.20, P < 0.01) had significant predictive effects on suicidal ideation.Conclusion Mental resilience plays a negative moderating effect between sleep quality and suicidal ideation. Tailored mental resilience training should be developed for officers and soldiers to improve their mental resilience, so as to attenuate the adverse effects of risk factors such as poor sleep quality.