ABSTRACT: Importance:In 2006, a US district court judge ordered tobacco companies to sponsor nationwide antismoking advertising campaigns. This landmark ruling and its subsequent execution represent an unprecedented tobacco control event; however, the association of this campaign with intentions and/or attempts to quit smoking is unknown. Objectives:To assess the reach of the expanded court-ordered tobacco industry antismoking advertisements (via television, newspapers, tobacco company websites, and/or cigarette packages), to examine associations between exposure to industry antismoking advertisements and intentions and/or attempts to quit smoking among cigarette smokers, and to calculate the numbers of US smokers who would have quit intentions associated with exposure to multiple advertisements. Design, Setting, and Participants:Data for this study were obtained from 5309 US adults, including 610 smokers, who responded to the Health Information National Trends Survey, a nationally representative cross-sectional survey conducted from January 22 to April 30, 2019. Respondents were representatives of households selected by equal-probability sampling of a database of US residential addresses. Exposure:Reported exposure to antismoking messages. Main Outcomes and Measures:Cigarette smoking cessation attempt in the past 12 months and intentions to quit cigarette smoking in the next 6 months. Covariates were age, sex, household annual income, race/ethnicity, educational level, and geographical residence. Data were weighted to be nationally representative after applying survey weights specified for the survey cycle. Results:The overall sample of 5309 respondents were a mean (SD) age of 55.6 (19.1) years and included 3073 women (51.2%), 3037 non-Hispanic white respondents (59.1%), 4645 respondents who lived in urban US areas (84.7%), and 610 current smokers (12.5%). Findings indicate that 2464 US adults (45.8%; 95% CI, 43.2%-48.5%) and 410 current smokers (66.8%; 95% CI, 61.1%-72.4%) were exposed to antismoking advertisements. Exposure to multiple antismoking messages was associated with 2.19 (95% CI, 1.10-4.34) greater odds of having intentions to quit cigarette smoking but was not associated with attempts to quit (adjusted odds ratio, 1.31; 95% CI, 0.69-2.52). Furthermore, an examination of the association of cumulative exposure to antismoking messages with cessation intentions revealed that, with each additional exposure to an antismoking message, the odds of smoking cessation intentions increased by 1.21 (95% CI, 1.02-1.44). If all smokers were to be exposed to multiple antitobacco messages, there could be an estimated 3.98 million (95% CI, 492?480-7?223?040) current smokers in the United States with intentions to quit. Conclusions and Relevance:Although the reach of court-ordered industry advertisements increased among smokers, the reach of these advertisements within the general population remains suboptimal. The finding that industry advertisements helped smokers consider quitting highlights their potential to aid smoking cessation. However, the lack of association with actual attempts to quit suggests that the industry antismoking advertisement campaigns were inadequate. The design and content of industry antismoking advertisement campaigns should be enhanced to help smokers quit.