The Adult Consumers of Tobacco Study (ACTS1) dataset contains intensive longitudinal survey data from all participants who completed at least part of the baseline survey from December 2020-October 2021. Participants included U.S. adults 21 years or older who were recent or current established cigarette smokers and recent initiators (or recent re-initiators) of electronic cigarettes. Those who screened as eligible and fully completed the baseline survey were invited to complete 11 weekly surveys and 3 quarterly surveys (at 6-, 9-, and 12-months post-baseline). In addition, a subset of participants were invited to complete a supplemental survey 3 days after the baseline, which assessed alcohol and tobacco co-use.