Objectives. To examine the prevalence of cannabis use among US workers using data from the US Behavioral Risk Factor Surveillance System (BRFSS) during 2016 to 2020. Methods. We analyzed past 30-day cannabis use among US workers. We calculated weighted prevalence and adjusted prevalence ratios (APRs) of cannabis use for working adults by industry groups, occupation groups, and sociodemographic characteristics (e.g., sex, education, age, race/ethnicity). Results. During the 5-year survey period, the weighted prevalence of past 30-day cannabis use among adult US workers from the 15 states included in the BRFSS was 10.7%. The industry group with the highest weighted prevalence of use was accommodation and food services (20.7%), and the highest-ranking occupation group was food preparation and service (21.9%). The industry group with the highest APR was accommodation and food services (APR = 1.31; 95% confidence interval [CI] = 1.10, 1.55), and the occupation group with the highest APR was arts, design, entertainment, sports, and media (APR = 1.91; 95% CI = 1.52, 2.41). Conclusions. Cannabis use among US workers varied widely by sex, age, race, education, industry groups, and occupation groups. A more accurate understanding of this variation can help guide research, focus policy discussions, and prioritize health messaging. (Am J Public Health. 2024;114(S8):S645-S653. https://doi.org/10.2105/AJPH.2024.307788).