Alcoholic beverages are carcinogenic to humans. Globally, an estimated 4.1% of new cancer cases in 2020 were attributable to alcoholic beverages. However, the full cancer burden due to alcohol is uncertain because for many cancer (sub)types, associations remain inconclusive. Additionally, associations of consumption with therapeutic response, disease progression, and long-term cancer outcomes are not fully understood, public awareness of the alcohol–cancer link is low, and the interrelationships of alcohol control regulations and cancer risk are unclear. In December 2020, the U.S. NCI convened a workshop and public webinar that brought together a panel of scientific experts to review what is known about and identify knowledge gaps regarding alcohol and cancer. Examples of gaps identified include: (i) associations of alcohol consumption patterns across the life course with cancer risk; (ii) alcohol's systemic carcinogenic effects; (iii) alcohol's influence on treatment efficacy, patient-reported outcomes, and long-term prognosis; (iv) communication strategies to increase awareness of the alcohol–cancer link; and (v) the impact of alcohol control policies to reduce consumption on cancer incidence and mortality. Interdisciplinary research and implementation efforts are needed to increase relevant knowledge, and to develop effective interventions focused on improving awareness, and reducing harmful consumption to decrease the alcohol-related cancer burden.