Using daily diary data, this study examined cross-day associations between family conflict and school problems and tested mediating effects of daily negative mood and moderating effects of psychological symptoms. For 2 weeks, parents and adolescents (N = 106; Mage = 15.4) reported daily conflict; adolescents reported daily negative mood and school problems. Results indicated bidirectional, multiday spillover between parent–adolescent conflict and school problems with daily negative mood statistically accounting for spillover both within and across days. Externalizing symptoms strengthened links between father–adolescent conflict and school problems, whereas depressive and anxious symptoms strengthened links between parent–adolescent conflict and daily negative mood. By demonstrating cross-domain transmission of daily problems, these findings highlight the salience of everyday events as possible intervention targets.