Background <p>Athlete engagement represents a critical construct for understanding optimal athletic functioning, yet the field lacks comprehensive theoretical models integrating its diverse correlates. While previous research has identified various factors influencing engagement, no systematic synthesis exists mapping all empirical evidence across populations, languages, and sporting contexts. This scoping review addresses this critical gap by providing the first comprehensive, systematic synthesis of all factors associated with athlete engagement, establishing the foundational evidence base necessary for theoretical model development and evidence-based interventions.</p> Methods <p>The review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines, Arksey and O’Malley’s five stages and the Joanna Briggs Institute methodology for scoping reviews. A comprehensive search was carried out in seven databases and 1428 papers were retrieved. After removing duplicates and applying eligibility criteria, 70 studies were assessed for eligibility. After removing papers of poor quality, unavailable papers and papers investigating other types of engagement, 48 papers published between 2007 and 2024 were selected for analysis.</p> Results <p>The majority of these papers were quantitative and cross-sectional, using the Athlete Engagement Questionnaire to measure athlete engagement. The review identified 41 correlates of athlete engagement, categorised as antecedents, consequences, mediators or related variables. Psychological factors, such as burnout, motivation, perfectionism and the coach-athlete relationship, were the most commonly studied.</p> Conclusions <p>The results highlight the significant role of burnout, motivation, perfectionism and the coach-athlete relationship in enhancing engagement and emphasise the importance of developing training programmes that address these factors in order to promote athlete engagement.</p> <p><i>Registration</i>: The following scoping review was appropriately registered on the Open Science Framework (<a href="https://doi.org/10.17605/OSF.IO/TWNZM">https://doi.org/10.17605/OSF.IO/TWNZM</a>).</p>