Amidst a global pandemic, people’ survival needs become salient and the ability for people to regulate feeling and actions might be particularly relevant to protecting oneself from harm. Regulatory Focus Theory (Higgins, 1998) proposes that people pursue their goals by having a focus on prevention (i.e., motivated by security) or promotion (i.e., motivated by pleasure). Prior research indicates that people focused on prevention (vs. promotion) are more likely to engage in health-protective behaviors, including sexual health behaviors, because they perceive more threats. Extending this reasoning to the sexual activity of single people during the COVID-19 pandemic, we conducted a pre-registered longitudinal study (N = 174) examining the role of regulatory focus on people’s sexual behaviors. As hypothesized, results showed that single people who reported having a more prevention focus at the onset of the pandemic perceived greater threats caused by the pandemic two weeks later, which, in turn, predicted less frequent sexual activity and engagement in sex with fewer sexual partners the following two weeks. These effects were consistent even when controlling for promotion (i.e., pleasure motivations), personality, gender, and sexual orientation. Findings are discussed considering their implications for the sexual functioning and sexual health of single people.