Introduction: The national smoking cessation program Stoptober was introduced in October 2012 in England and in October 2014 in the Netherlands. There is little evidence on the extent to which the Stoptober program has an impact on smoking-related outcomes at national levels. We aimed to measure the magnitude and timing of the associations of the Dutch Stoptober program with searching for smoking cessation on the internet. Methods: An interrupted time series analysis was used on Google search queries. Data were seasonally adjusted and analyzed using autoregressive integrated moving average (ARIMA) modelling. To examine the magnitude and timing of the program, nine potential intervention periods around early October were analyzed simultaneously, with control for national tobacco control policies. Parallel analyses were made of Belgium as a control group. Results: The 2014–2016 Dutch Stoptober programs were associated with a significant increase in relative search volume (RSV) in the week the challenge starts (11%, 95% CI: 1–21), the next week (22%, 95% CI: 12–33) and the week afterward (17%, 95% CI: 8–27). A smaller, non-significant increase was observed in the two weeks before the challenge. No substantial increases were found in the Belgian control group. Conclusions: In the Netherlands, the Stoptober program was associated with a substantial short-term increase in information seeking for smoking cessation. This suggests that Stoptober may be able to affect smoking-related outcomes in national populations at large.