Background and aim: Social networking sites (SNS) are interactive internet-based social platforms that facilitate information sharing. A growing body of literature on exposure to, and self-posting of, alcohol-related content on SNS has examined the relationship between SNS use and alcohol consumption in young people. This study aims to synthesise the literature exploring the relationship between exposure (i.e. viewing or listening of alcohol-related media) and self-posting (i.e. uploading images or text of alcohol content) of alcohol-related media on SNS on alcohol consumption. Methods: A pre-registered systematic review was conducted in June 2022 within PubMed, Scopus, PsycINFO and Web of Science. Original prospective and cross-sectional studies assessing youth and young adults (≤ 24 years of age) that measured exposure to alcohol-related media or posting of alcohol-related content on SNS and self-reported alcohol consumption outcomes were included. Meta-analyses were conducted on comparable methodologies. Results: Thirty studies were included (n = 19,386). Meta-analyses of cross-sectional studies showed both greater exposure (five studies; pooled β = 0.34, 95% confidence interval [CI] = 0.23, 0.44, i2 = 27.7%) and self-posting of alcohol-related content (six studies; pooled β = 0.57, 95%CI = 0.25,0.88, i2 = 97.8%) was associated with greater alcohol consumption. Meta-analyses of three prospective studies also identified that greater exposure predicted greater future alcohol consumption (three studies; pooled β = 0.13, 95%CI = 0.11,0.15, i2 = 0.0%). Narrative analyses of studies that could not be meta-analysed due to incompatible methodologies were also conducted. Most studies (all four prospective, one of two cross-sectional) identified positive associations between exposure to alcohol-related content and greater average consumption. Most studies (three of four prospective, four of six cross-sectional) reported a positive association between of alcohol-related self-posting and greater average alcohol consumption. Conclusions: Both exposure to, and self-posting of, alcohol-related content on social networking sites are positively associated with current average consumption, problem drinking, and drinking frequency.