Background: Do young adults have low compliance rates with public health measures aimed at curbing the spread of Coronavirus disease 2019 (COVID-19)? This paper leverages a prospective-longitudinal cohort study with data before and during the pandemic to examine this question.Methods: Data came from an ongoing cohort study (n=737). Non-compliance with public health measures and concurrent correlates were measured at age 22. Antecedent sociodemographic, social, and psychological factors were measured at ages 15-20.Findings: Young adults generally complied with COVID-19 public health measures, although compliance with some measures (e.g., cleaning/disinfecting mobile phones, standing 1.5-2 meters apart) was relatively lower. Non-compliance, especially with hygiene-related measures, was more prevalent in males, and in individuals with higher education, higher SES, and a non- migrant background. Non-compliance was associated with “antisocial potential,” including pre-pandemic low acceptance of moral rules, legal cynicism, low shame/guilt, low self-control, engagement in delinquent behaviors, and association with delinquent peers. Young adults with low trust, including in the government’s measures for fighting the virus, also complied less.Interpretation: In order to increase voluntary compliance with COVID-19 measures, public health campaigns should implement strategies that foster moral obligation and trust in authorities, or leverage trustworthy individuals in the community to disseminate information. For young adults with low self-control, self-monitoring, environmental restructuring, or nudging may increase compliance. Long-term investments into integrating antisocial youth into society may decrease rule-breaking behaviors, including during pandemics when compliance saves lives.