Vanessa is a youth-led service promoting road safety at music festivals. We conducted a cross-sectional survey at 23 festivals in Victoria, Australia to investigate alcohol and illicit drug use among attendees aged ≥16 years who visited Vanessa. Participants completed the Alcohol Use Disorders Identification Test - Consumption (AUDIT-C) and reported recent illicit drug use and intentions to use drugs at festivals. Multinomial and logistic regression identified correlates of risky drinking and drug use. 2305 participants were recruited (60% female, median age 22). Most (98%) consumed alcohol in the past year and 26% had high-risk AUDIT-C scores. Almost half (48%) reported recent drug use and 24% intended to use drugs at festivals. Females had lower odds than males of recent drug use [adjusted odds ratio (AOR)=0.49, 95% confidence interval (CI)=0.38, 0.62], intending to use drugs at festivals (AOR = 0.60, CI = 0.45, 0.80) and lower risk of high-risk drinking (adjusted relative risk ratio (ARRR)=0.35, CI = 0.27, 0.47). Attending electronic music festivals was associated with high-risk drinking (ARRR = 2.07, CI = 1.14, 3.72), recent drug use (AOR = 2.23, CI = 1.42, 3.51) and intending to use drugs at festivals (AOR = 1.90, CI = 1.15, 3.14). Vanessa was a useful setting to reach young people reporting risky alcohol consumption and illicit drug use. Genre of music festivals may be useful for tailoring harm reduction strategies