declared a global pandemic of coronavirus disease 2019 (COVID-19), which has exacted a massive global impact on health, politics and the economy. 1 With some jurisdictions past the peak of the first wave, the strain on the health care system is becoming apparent-specifically, the impact on surgical care. 2 The CovidSurg Collaborative estimated that 28 404 603 surgeries would be cancelled or postponed across 190 countries in the initial 12 weeks of COVID-19, including 37.7% of cancer surgeries and 81.7% of other (benign) surgeries. 3 If countries increased normal surgical volume by 20%, it would take a median of 45 weeks to clear the backlog. Modelling postpandemic recovery for elective orthopedic surgery in the United States suggested it would take 7-16 months to reach a steady state with a backlog of more than 1 million surgeries. 4 On Mar. 15, 2020, Ontario's Ministry of Health directed hospitals to begin a measured "ramping down of elective surgeries and other nonemergent clinical activity" in anticipation of a COVID-19 surge. 5 On May 26, 2020, the Ministry of Health lifted the directive, allowing hospitals to gradually increase elective and time-sensitive surgeries. 6 The reduction in nonemergent surgeries in Ontario because of COVID-19 has created a substantial surgical backlog. Our objective was to estimate the size of the nonemergent surgical backlog owing to COVID-19 in Ontario, and the time and resources required to clear this backlog. Methods The framework for developing these estimates is outlined in Figure 1. At the recommendation of our regional and hospital partners for feasible surge scenarios, we considered a +10% (1 d per week at 50% capacity) surge scenario, adding 8 hours per day incremental to a 5-day operating week. We included surgeries performed in a fully equipped operating room and categorized RESEARCH HEALTH SERVICES