This study examines the direct effect of family communication on adolescents’ school adjustment and its indirect effects through executive function difficulties and empathy. Data were drawn from the 15th wave (2022) of the Panel Study on Korean Children (PSKC), with a sample of 1,142 adolescents (589 boys and 553 girls). Structural equation modeling was conducted using SPSS 22.0 and AMOS 22.0. The results showed that family communication had a significant direct effect on school adjustment. In addition, executive function difficulties and empathy independently mediated the relationship between family communication and school adjustment. A significant sequential mediation effect was also found, indicating that family communication influenced school adjustment through executive function difficulties and empathy in sequence. These findings highlight the importance of family communication as a key environmental factor, as well as executive function and empathy as critical individual factors, in promoting adolescents’ school adjustment. Enhancing executive function and empathy, alongside fostering open and positive family communication, may be particularly effective in supporting successful school adjustment during adolescence. The results suggest implications for intervention programs targeting adolescents’ cognitive and socio-emotional development, as well as parent education programs that promote constructive family communication.