Life satisfaction can both affect and be affected by occupational factors in military personnel. Perceived stress is considered an important predictor of life satisfaction. The objective of this study is to evaluate the direct and indirect effects of perceived stress on life satisfaction and the mediating role of depression, anxiety, and sleep quality among Iranian military personnel. In this cross-sectional study, a total of 301 military personnel were investigated by using standard self-report questionnaires, consisting of the Revised Symptom Checklist-90 (SCL-90-R), Pittsburgh Sleep Quality Index (PSQI), Perceived Stress Scale (PSS), and Satisfaction with Life Scale (SWLS) in our study. Data analysis was conducted using descriptive statistics, the Pearson correlation coefficient, ordinary least square regression, and the bootstrap method. The direct effect of perceived stress on life satisfaction was significant. Perceived stress also affects life satisfaction indirectly through single mediation of sleep quality; serial multiple mediations of anxiety as the first and sleep quality as the second mediator; and the serial multiple mediations of depression, anxiety, and sleep quality, as the first to the third mediator, respectively. Lower levels of perceived stress, depression, and anxiety, along with better sleep quality, are correlated to higher levels of life satisfaction in military personnel. There are several points of prevention and intervention in order to increase the life satisfaction of military personnel, which can improve their quality of life and occupational efficiency.