The COVID-19 pandemic has deleteriously impacted physical and mental health. Guidelines to limit the spread of COVID-19 include wearing a face covering in public, limiting close contacts, and physical distancing. In combatting this and future pandemics, it is essential to understand predictors of adherence, such as psychological flexibility. We hypothesized higher psychological flexibility would relate to greater adherence to public health guidelines. Participants (n = 265) were English-reading/speaking adults in the United States and were recruited through Amazon’s Mechanical Turk. Included in the present analyses are data from June (n = 360) and July 2020 (n = 265). Measures included the Comprehensive Assessment of ACT Processes (CompACT), which measured psychological flexibility. Outcome measures included mask-wearing and number of close contacts, which were operationalized categorically (100% mask-wearing in public, ≤10 close contacts in past week). Two logistic regression models examined psychological flexibility and distress as predictors of adherence to mask-wearing and limiting close contacts, while controlling for demographic correlates. Results indicated that greater behavioral awareness predicted greater odds of mask-wearing and limiting close contacts. Psychological flexibility, and behavioral awareness specifically, should be investigated in future research as targets for intervention amidst global disasters.