<p>Economic hardship negatively influences youth development, operating through direct and indirect pathways that disrupt family functioning. Financial strain, the subjective perception of economic hardship, may be a pivotal mechanism linking family financial challenges to youth maladjustment, particularly when examined alongside family conflict and child behavior. Using three annual waves from the Adolescent Brain &amp; Cognitive Development (ABCD) study (<i>N</i> = 11,868), this study evaluated whether financial strain predicts youth problem behaviors (internalizing and externalizing) via family conflict and whether this pathway operates independently of income level. We used parent-reported financial strain and youth-reported family conflict, emphasizing children’s perspectives on their family environment. Mediation models controlled for prior levels of all variables and family income and examined child sex as a potential moderator. Results demonstrated that more financial strain significantly predicted greater family conflict, which in turn mediated the effect of financial strain on both internalizing and externalizing behaviors two years later, even after accounting for income and past conflict and problem behaviors. Moderated mediation analyses indicated no significant differences by child sex. This study underscores the pivotal role of financial strain in shaping family conflict and youth maladjustment, regardless of socioeconomic background. By focusing on children’s perceptions of family dynamics, this work contributes to a more holistic understanding of the family environment and identifies intervention targets to mitigate the cascading effects of economic hardship on youth.</p>