<p>Research has extensively examined the association between self-acceptance and life satisfaction. However, studies investigating the directional relationship between self-acceptance and life satisfaction, particularly in adolescent populations, remain limited. Moreover, it is unclear whether cognitive reappraisal serves as a mediator in the directional relationship between adolescents’ self-acceptance and life satisfaction, and whether there are potential gender differences in these associations. To address this gap, a one-year longitudinal study was performed using data collected at three waves from 1566 Chinese high school students (aged 14–16 years, <i>M</i>_age = 15.18, <i>SD</i> = 0.48, 49.20% male). The results of cross-lagged panel models revealed a bidirectional relationship between self-acceptance and life satisfaction, and indicated that cognitive reappraisal mediated the lagged association from self-acceptance to life satisfaction. Additionally, no significant gender differences were found in the bidirectional relationship or in the mediating role of cognitive reappraisal. These findings deepen the understanding of the longitudinal relationships among adolescents’ self-acceptance, cognitive reappraisal, and life satisfaction, and highlight the importance of enhancing self-acceptance and cognitive reappraisal skills to support adolescents’ life satisfaction.</p>