Context: Lack of education, stigma and negative self-attitudes are key barriers to help-seeking in Gaelic footballers. With the prevalence of mental health issues in Gaelic footballers and the increased risk of experiencing mental health issues following injury, mental health literacy (MHL) interventions are necessary. Objective: To design and implement a novel MHL educational intervention program in Gaelic footballers. Design: Controlled laboratory study. Setting: Online. Patients or Other Participants: Elite and sub-elite Gaelic footballers, including an intervention (n=70* ; 25.1±4.5years) and control group (n=75; 24.4±6.0years). * [Eighty-five participants were recruited to the intervention group but n=15 dropped out after completing baseline measures.] Interventions: A novel educational intervention program, ‘GAA and Mental Health–Injury and a Healthy Mind’, was designed to address the key components of MHL and was underpinned by the Theory of Planned Behavior, and the Help-Seeking Model. The intervention was implemented online via a brief, 25-minute presentation. Main Outcome Measures: Measures of stigma, help-seeking attitudes and MHL were completed by the intervention group at baseline, immediately post-attendance at the MHL program and 1-week and 1-month post-intervention. The control group completed the measures at similar time points. Results: Stigma significantly decreased and attitudes to help-seeking and MHL significantly increased in the intervention group from baseline to post-intervention (p<0.05), with significant differences sustained at 1-week and 1-month follow-up. Our results showed significant differences in stigma, attitude and MHL between groups across time points. Intervention participants provided positive feedback and the program was appraised as informative.