We sought to evaluate the association between patient sociodemographic status and breast screening volumes (BSVs) during the COVID-19 pandemic in a large, population-based breast screening program that serves a provincial population of over 5 million. Methods: All patients who completed breast screening between April 1st, 2017 and March 31st, 2021 were eligible to participate. An average of 3 annual periods between April 1st, 2017 and March 31st, 2020 were defined as the pre-COVID period while the period between April 1st, 2020 and March 31st, 2021 was defined as the COVID-impacted period. The Postal CodeOM Conversion File Plus was applied to map patient residential postal codes to 2016 census standard geographical areas, which provided information on community size, income quintile and dissemination areas. Dissemination areas were subsequently linked to the Canadian Index of Multiple Deprivation (CIMD). Overall BSV was reduced by 23.0% during the COVID-impacted period as compared to the pre-COVID period. Percent reductions in BSVs were greatest among younger patients aged 40 to 49years (31.3%) and patients residing in communities with a population of less than 10,000 (27.0%). Percent reduction in BSV was greatest among patients in the lowest income quintile (28.1%). Percent reductions in BSVs were greatest for patients in the most deprived quintiles across all 4 dimensions of the CIMD. Disproportionate reductions in BSVs were observed during the COVID-19 pandemic among younger patients, patients residing in rural communities, patients in lower income quintiles, and patients in the most deprived quintiles across all 4 dimensions of the CIMD.