Introduction Alcohol consumption creates a significant public health burden, and young people who drink alcohol place themselves at risk of harm. Expert guidance and reviews have highlighted the pressing need for reliable and valid, age-appropriate alcohol screening and assessment measures for young people. The proposed systematic review will evaluate existing alcohol screening and assessment measures for young people aged 24 and under. Methods and analysis Six electronic databases will be searched for published and grey literature. In addition, reverse and forward citation searching and consultation with experts will be performed. Three sets of search terms will be combined, including alcohol use/problems, young people and validation studies. The titles and abstracts of reports from the searches will be screened, and potentially relevant full-text reports will be retrieved and independently assessed for inclusion by two reviewers based on prespecified criteria. Discrete validation studies within included reports will then be assessed for eligibility. There will be an a priori basic quality threshold for predictive validity, internal and test–retest for studies to warrant full data extraction. Studies above the quality threshold will be assessed for quality using the modified consensus-based standards for the selection of health measurement instruments checklist and a quality assessment tool for diagnostic accuracy studies. Dissemination This review will highlight the best performing measures both for screening and assessment based on their psychometric properties and the quality of the validation studies supporting their use. Providing clear guidance on which existing measures perform best to screen and assess alcohol use and problems in young people will inform policy, practice and decision-making, and clarify the need for further research.