BackgroundMaternal relationship quality is associated with mental health; maternal mental health could affect child mental health. The COVID-19 pandemic adversely affected both relationship quality and mental health. PurposeTo examine if maternal distress mediates the association between pandemic-related changes in maternal relationship quality and child distress. MethodsA sample of 194 mother-child dyads were from the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort participated. Mothers reported pandemic-related changes in relationship quality (partner, child, friends/family) and mental health (anxiety, depressive symptoms). Children (7-10 yrs) self-reported mental health (anxiety, depressive symptoms). Covariates were maternal sociodemograhics, child age and gender, number of children in the home, time between pandemic start and assessments, and pandemic change in household income. Mediation was tested using the SPSS PROCESS macro. ResultsAn indirect effect of maternal relationship quality on child anxiety via maternal depressive symptoms was detected, .95CI upper boundary <-.025. Decreases in partner relationship quality, b = -.45, SE = .23, p = .001, and relationship quality with friends or family outside the household, b = -.46, SE = .27, p = .001, were associated with higher maternal anxiety, which in turn, predicted higher child depressive symptoms, p’s<.014. ConclusionsPandemic-related decreases in maternal relationship quality were associated with maternal distress, which in turn was associated with child distress. LimitationsWe focused on mothers only and obtained retrospective recall reports on changes in relationship quality during the pandemic.