ABSTRACT Objective: To describe the prevalence of alcohol consumption before and during the COVID-19 pandemic and to analyze the factors associated with this behavior during the period of social distancing among Brazilian adolescents. Methods: Cross-sectional study using data from the ConVid Adolescents survey, carried out via the Internet between June and September 2020. The prevalence of alcohol consumption before and during the pandemic, as well as association with sociodemographic variables, mental health, and lifestyle were estimated. A logistic regression model was used to assess associated factors. Results: 9,470 adolescents were evaluated. Alcohol consumption decreased from 17.70% (95%CI 16.64–18.85) before the pandemic to 12.80% (95%CI 11.85–13.76) during the pandemic. Alcohol consumption was associated with the age group of 16 and 17 years (OR=2.9; 95%CI 1.08–1.53), place of residence in the South (OR=1.82; 95%CI 1.46–2.27) and Southeast regions (OR=1.33; 95%CI 1.05–1.69), having three or more close friends (OR=1.78; 95%CI 1.25–2.53), reporting worsening sleep problems during the pandemic (OR=1.59; 95%CI 1.20–2.11), feeling sad sometimes (OR=1,83; 95%CI 1,40–2,38) and always (OR=2.27; 95%CI 1.70–3.05), feeling always irritated (OR=1,60; 95%CI 1,14–2,25), being a smoker (OR=13,74; 95%CI 8.63–21.87) and a passive smoker (OR=1.76; 95%CI 1.42–2.19). Strict adherence to social distancing was associated with lower alcohol consumption (OR=0.40; 95%CI 0.32–0.49). Conclusions: The COVID-19 pandemic led to a decrease in consumption of alcoholic beverages by Brazilian adolescents, which was influenced by sociodemographic and mental health factors, adherence to social restriction measures and lifestyle in this period. Managers, educators, family and the society must be involved in the articulation of Public Policies to prevent alcohol consumption.