In the present paper, we introduce an ecological view of career transitions. We consider an athlete’s development as a journey through various athletic and non-athletic environments that support their striving for career excellence. On this journey, an athlete experiences a multitude of environments and transitions from one environment (e.g., one club, one country or one sport) to another. To develop this understanding, we introduce the concept of a transition environment defined as a dynamic and temporary system that bridges the setting that an athlete is transitioning from and to. We also suggest two working models that in unison can work as a roadmap for transition environment research and practice. The transition environment (TE) model helps to describe the TE and the transition environment success factor (TE-SF) model helps to understand why certain TEs are more successful than others supporting athletes in transition. The models can be used by researchers studying specific transition environments to understand how such environments facilitate or hinder transitions, and by practitioners (coaches, managers, sport psychologists) to support athletes’ transitions by improving their TEs. We hope the idea of an ecology of athlete transitions will find its way into empirical studies of different types of transitions (e.g., to another sport, to another level in sport, to another club or to another country) in multiple cultural contexts and contribute to the development of career-long psychological support services. © 2023 International Society of Sport Psychology.