Risk-taking is associated with increased morbidity and mortality among adolescents, with insufficient sleep a potential factor contributing to heightened risk-taking propensity in this age group. A systematic review of the evidence examining the relationship between sleep duration and risk-taking in adolescents was conducted using PsycINFO, PubMed, Medline, Scopus, and CINAHL databases. These searches identified 26 studies including 579,380 participants, 24 of which were appropriate for meta-analysis. Pooled results indicated that insufficient sleep was associated with 1.43 [1.26, 1.62] times greater odds of risk-taking. This relationship was witnessed across diverse categories of risk-taking, including alcohol use, drug use, smoking, violent/delinquent behaviour, transport risk-taking/road safety, sexual risk-taking and trait risk-taking. Risk of bias analysis showed that the quality of the included studies was mixed. Further, few studies utilized either longitudinal or experimental designs, thus limiting causal conclusions. These findings highlight the importance of further research to examine the causal relationship between sleep duration and risk-taking and to elucidate the mechanisms that underpin this relationship.