Aims: To estimate the industry-specific impact of the COVID-19 pandemic (Omicron wave) on sick leave. Methods: Using individual-level data from the Norwegian Emergency Preparedness Register, the study covers all workers in different industries ( N = 2,733,751 people) on a monthly level in the time periods January–March 2017–2020 (except March 2020) and 2022 (38,199,536 person-months). We estimated the industry-specific increase in monthly average sick leave during the Omicron wave in 2022 compared with the corresponding months in 2017–2020. Results: We found an average increase in monthly sick leave rates of 2.92 percentage points (95% CI 2.9–2.94) during the three first months of 2022. The increases were strongest within food and accommodation (4.42 percentage points increase, 95% CI 4.33–4.51) and administrative support services (3.94 percentage points increase, 95% CI 3.85–4.03). Conclusions: The Omicron wave resulted in a substantial increase in sick leave, which was unevenly distributed across industries. The results of this study highlight the importance of industry-specific contingency planning when facing the rapid spread of infectious diseases.