Background Understanding the psychosocial status of children and adolescents during the COVID-19 pandemic is vital to the appropriate and adequate allocation of social supports and mental health resources. This study evaluates the burden of mental health concerns and the impact of demographic factors while tracking mental health service recommendations to inform community service needs. Methods MyHEARTSMAP is a digital self-assessment mental health evaluation completed by children and their guardian throughout British Columbia between August 2020 to July 2021. Severity of mental health concerns was evaluated across psychiatric, social, functioning, and youth health domains. Proportional odds modelling evaluated the impact of demographic factors on severity. Recommendations for support services were provided based on the evaluation. Results We recruited 541 families who completed 424 psychosocial assessments on individual children. Some degree of difficulty across the psychiatric, social, or functional domains was reported for more than half of children and adolescents. Older youth and those not attending any formal school or education program were more likely to report greater psychiatric difficulty. Girls experienced greater social concerns, and children attending full-time school at-home were more likely to identify difficulty within the youth health domain but were not more likely to have psychiatric difficulties. Considerations to access community mental health service were triggered in the majority (74%) of cases. Conclusions Psychosocial concerns are highly prevalent amongst children and adolescents during the COVID-19 pandemic. Based on identified needs of this cohort, additional community health supports are required, particularly for higher risk groups.