Female collegiate athletes are at significantly greater risk than their non-athlete peers for developing eating disorders. One plausible explanation for this increased risk is offered by Self-Determination Theory (SDT), according to which athletes who perceive themselves to be experiencing high levels of autonomy, competency, and relatedness will experience greater self-determined motivation (SDM) and ultimately less disordered eating behaviors (DE). The present study employed a combined survey-experimental design through an online questionnaire to investigate mediational relationships among coaching and parenting styles, psychological need satisfaction (PNS), SDM, and DE, as well as the causal impact of PNS on athletes’ SDM and DE. Participants were varsity female athletes (N = 113) at a Division III liberal arts college in the Mid-Atlantic United States. Mediational analyses revealed a significant indirect effect of coaching style on SDM through psychological need satisfaction, as well as significant total and direct effects of parenting style on SDM. Results from a factorial ANOVA indicated a significant effect of direction of psychological need satisfaction on SDM. Although no significant findings were evident for DE, the present study offers empirical support for the associations among coaching and parenting styles, PNS, and SDM, and suggests the implementation of longitudinal designs to more accurately assess the relationships among those variables and DE.