Plain Language SummaryDrug use presents significant concerns for health, economics, and society globally. Research highlights the pivotal role of personality traits in understanding drug use. This study aims to contribute to the existing literature by exploring how personality traits at age 10 correlate with drug use at age 30. Utilizing data from the British Cohort Study 1970, we obtained five personality traits from both teacher-completed and self-completion questionnaires when participants were 10 years old. The relationship between personality traits and drug use was examined by employing a probit model. Children exhibiting lower levels of conscientiousness/agreeableness or higher levels of extraversion/internal locus of control at age 10 were more inclined to engage in drug use in adulthood. Moreover, significant differences based on gender and the types of drugs used were observed. These findings might be valuable to policymakers, as they could introduce interventions tailored to specific personality traits to mitigate their adverse effects. For instance, they could offer emotional regulation training for children with low levels of conscientiousness or engage children with high extraversion in stimulating activities such as sports, creative arts, or music.