Importance: Smoking cessation is an urgent public health priority given that smoking is associated with increased risk of severe COVID-19 outcomes and other diseases. It is unknown how smoking cessation changed nationally during the COVID-19 pandemic.

Question: Did smoking cessation–related behaviors change during the COVID-19 pandemic in the US?

Findings: This cross-sectional study among 788 008 US adult smokers found that the annual prevalence of past-year quit attempts decreased for the first time since 2011, from 65.2% in 2019 to 63.2% in 2020. Simultaneously, observed sales of nicotine replacement therapy brands from representative retail scanner data across 31 US states decreased by 1% to 13% compared with expected sales.

Meaning: These findings suggest a decrease in smoking cessation activity during the COVID-19 pandemic and the need to reengage smokers in evidence-based quitting strategies.