Mindfulness can play a critical role in promoting and protecting mental wellbeing among elite athletes. However, mechanisms of change are needed to provide theoretical insight when designing mindfulness-based programs in this population. The purpose of this study was to explore how mindfulness predicts mental wellbeing through the attitudes of gratitude (toward pleasant moments) and self-compassion (toward unpleasant moments). All outcomes were assessed through self-reported scores on the trait levels. The convenience sample consisted of 226 elite athletes (Mean age = 21.44 years; SD = 3.47; 52.2 % Men), of which mostly resided in Australia (52.2 %) and Sweden (37.2 %). The parallel mediation analysis was conducted via PROCESS macro and covariates were added into the analysis, including age, gender, type of sport, fitness status, and country of residence. Results indicated trait gratitude and trait self-compassion were parallel mediators of the relationship between trait mindfulness and mental wellbeing. Researchers and practitioners in sport can consider cultivating elite athletes' attitudes of gratitude and self-compassion through mindfulness-based programs, which may help optimally promote and protect athlete wellbeing.