Abstract Objective Within an integrated framework based on theories of youth development and technological addictions, this study aimed to examine whether the relation between family conflict and problematic smartphone use (PSU) would be mediated or moderated by three resiliency components (i.e., tenacity, strength, and optimism). Background Adolescents are vulnerable to PSU, which is strongly associated with family environment, yet the association of family conflict with PSU and its psychological mechanisms have been overlooked. Method Two‐stage random sampling was used to recruit 1,372 adolescents (52.6% male; M age = 14.52 years, range = 11–19 years) from Macao, China. Path analysis with bootstrapping for mediation testing and PROCESS Macro's Model 1 for moderation testing were conducted. Results Family conflict was significantly associated with all resiliency components negatively and with PSU positively, while only two resiliency components were significantly associated with PSU: β = −0.16, p < .01 for tenacity and β = 0.11, p < .01 for optimism. Bootstrapping results showed that the positive association between family conflict and PSU was partially mediated by tenacity (β = 0.021, 95% confidence interval [0.007, 0.039]) and optimism (β = −0.014, 95% confidence interval [−0.028, −0.004]) but not by strength. However, all three resiliency components played nonsignificant moderating roles on the link between family conflict and PSU. Conclusion Family conflict is a risk factor for low resiliency and high vulnerability to PSU. Among three resiliency components, tenacity plays a protective role against PSU, whereas optimism seems to serve as a risk factor for PSU. Tenacity should be prioritized while the risk of (excessive) optimism should be noted in resiliency‐focused intervention for adolescent PSU.