Self-regulation is essential for optimal development, performance, and well-being in sport, and smartphones may support and hinder this self-regulation. The relationship between smartphones and self-regulation has seldom been investigated in sport. Thus, the purpose of this study was to examine self-regulatory processes, conditions, and outcomes related to athletes’ smartphone usage. Twenty-four competitive and high-performance athletes from eight sports participated in individual interviews informed by the models of self-regulated learning and self-regulatory strength. Themes created from a directed content analysis aligned with components of both models and were integrated with new themes to form the “Self-regulation and Smartphone Usage Model” (SSUM). The SSUM illustrates a cyclical model of self-regulation and smartphone usage across five components: self-regulation capacity, processes, conditions, outcomes, and competencies. While self-regulation demands can be increased because of smartphones and lead to depletion, smartphones can be powerful vehicles to strengthen self-regulation competencies.