Issues. Event-level alcohol research can inform prevention efforts by determining whether drinking contexts-such as people or places-are associated with harmful outcomes. This review synthesises evidence on associations between characteristics of adults' drinking occasions and acute alcohol-related harm. Approach. We systematically searched Ovid MEDLINE, Ovid PsycInfo and the Web of Science Social Sciences Citation Index. Eligible papers used quantitative designs and event-level data collection methods. They linked one or more drinking contexts to acute alcohol-related harm. Following extraction of study characteristics, methods and findings, we assessed study quality and narratively synthesised the findings. PROSPERO ID: CRD42018119701. Key Findings. Searches identified 95 eligible papers, 65 (68%) of which study young adults and 62 (65%) of which are set in the United States, which limits generalisability to other populations. These papers studied a range of harms from assault to drink driving. Study quality is good overall although measures often lack validation. We found substantial evidence for direct effects of drinking context on harms. All of the contextual characteristics types studied (e.g. people, place, timing, psychological states, drink type) were consistently associated with harms. Certain contexts were frequently studied and associated with harms, in particular, weekend drinking, drinking in licensed premises and concurrent illicit drug use. Implications. The findings of our review indicate target drinking contexts for prevention efforts that are consistently associated with increased acute alcohol-related harm. Conclusion. A large range of contextual characteristics of drinking occasions are directly associated with acute alcohol-related harm, over and above levels of consumption. [Stevely AK, Holmes J, McNamara S, Meier PS. Drinking contexts and their association with acute alcohol-related harm: A systematic review of event-level studies on adults' drinking occasions. Drug Alcohol Rev 2020;39: [309][310][311][312][313][314][315][316][317][318][319][320]