Youth amateur sporting environments present an untapped, under-researched, and potentially vital avenue for targeted mental health intervention programs. This study evaluates such an intervention in 12 sporting clubs, comprising of 330 Australian youth aged 12–15 years (M = 13.73, SD = 0.79). Mental health literacy, help-seeking intentions, and help-seeking behaviors were measured throughout the season using a repeated-measures experimental-control design. Multilevel modelling revealed the intervention successfully improved mental health literacy and help-seeking intentions in particular cohorts, such as youth scoring low in these constructs pre-intervention and youth who had not previously received the intervention. This study demonstrates the efficacy of interventions to effect positive change in amateur sporting youth, highlighting a convenient method to improve mental health in young people.