To estimate specific proximal and distal effects of COVID-19-related restrictions on families on children's adjustment problems, we conducted a six-site international study. In total, 2516 parents from Australia, China, Italy, Sweden, the United Kingdom, and the United States of America living with a young child (Mage = 5.77, SD = 1.10, range = 3 to 8 years, 47.9% female) completed an online survey between April and July 2020. The survey included the Strengths and Difficulties Questionnaire and family risk factors (parent distress, parent-child conflict, couple conflict, and household chaos) as well as a scale to index COVID-19-related family disruption. Our analyses also included public data on the stringency of national restrictions. Across the six sites, parental responses indicated elevated levels of hyperactivity, conduct, and emotion problems in children from families characterized by heightened levels of parent distress, parent-child conflict, and household chaos. In contrast, increased peer problems were more strongly related to COVID-19-related social disruption and stringency measures. Mediation models demonstrated that associations between COVID-19 social disruption and child difficulties could be explained by parental distress. Taken together, these results suggest that although the experience of the pandemic differed across countries, associations between COVID-19-related family experiences and child adjustment difficulties were similar in their nature and magnitude across six different contexts. Programs to support family resilience could help buffer the impact of the pandemic for two generations.