Arne Bouten

(1) Background: Sports participation offers vital physical, psychological, and social benefits, yet dropout rates remain high. Drawing on Self-Determination Theory, previous research has primarily analyzed dropout from an individual-centered perspective. This study extends the literature by examining how the motivational orientations of coaches and peers relate to athletes’ dropout intentions; (2) Method: Data were collected from 268 athletes and 50 coaches in Flanders (Belgium). Coach–athlete interdependencies were analyzed using the Actor–Partner Interdependence Model for one-with-many designs, while peer dynamics were assessed using the Group Actor–Partner Interdependence Model; (3) Results: Analyses of coach–athlete interdependencies revealed robust individual actor effects but no partner effects. Analyses of peer dynamics indicated that dropout intentions were also related to the combination of athletes’ own and their peers’ motivation. Athletes reported higher dropout intentions when their identified regulation was low relative to that of their peers. Amotivation displayed a paradoxical pattern: athletes’ own amotivation was associated with higher dropout intentions, whereas higher peer amotivation, and a smaller discrepancy between an athlete’s own and their peers’ amotivation, was associated with lower dropout intentions. These exploratory findings require replication; (4) Conclusions: Integrating analyses of coach–athlete and peer motivational interdependence highlights the importance of considering the broader team motivational context when addressing intentions to drop out of sport.