Spillover from interparental conflict (IPC) to the parent-child relationship is a risk factor for adolescent emotional, social, and behavioral maladjustment. Parental depression increases the risk for more frequent and intense IPC over periods of months to years, but relatively little is known about whether parental depressive symptoms increase the risk for IPC and/or the propensity for spillover on short timescales. Using daily diary methods, we tested two hypotheses to evaluate whether parental depressive symptoms predict increased risk for IPC spillover: (a) a stress generation hypothesis, in which higher levels of parental depressive symptoms are associated with a greater tendency to experience IPC, which elevates risk for spillover, and (b) a spillover propensity hypothesis, in which parental depressive symptoms strengthen the within-person linkage between daily couple conflict and poorer parent-adolescent relations. We analyzed data from 150 adolescents and caregivers from two-caregiver families who completed baseline and 21-day daily diary surveys. Consistent with a stress generation hypothesis, parents who were higher in baseline depressive symptoms reported higher levels of IPC over 21 days. At the daily level, there was evidence of spillover from IPC to higher parent-adolescent conflict and lower parent-adolescent closeness, but there was no evidence for increased propensity for spillover by parents' baseline depressive symptoms or daily depressed mood. Rather, there was a direct association between higher daily parental depressed mood and poorer daily parent-adolescent relationship quality (lower closeness, higher conflict). Ameliorating parental depressive symptoms may improve parent-adolescent relationship quality directly, as well as indirectly by decreasing the risk for IPC. (PsycInfo Database Record (c) 2024 APA, all rights reserved).