Background <p>Depressive symptoms were prevalent among breast cancer (BC) patients. This study aimed to examine the associations among self-control, spiritual well-being, hope, and depressive symptoms and to explore the chain mediating effect of spiritual well-being and hope in these associations among BC patients in China.</p> Methods <p>&#xa0;A total of 458 BC patients (effective response rate: 91.6%) entered this cross-sectional study. Questionnaires included the Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being, the Brief Self-Control Scale, the Herth Hope Index, the Self-Rating Depression Scale, and demographic variables. The Bootstrap analysis was used to test the mediating effect of spiritual well-being and hope.</p> Results <p>The mean score of depressive symptoms was 57.59 ± 6.17.&#xa0;The prevalence of depressive symptoms was 79.3% among Chinese BC patients. Depressive symptoms were significantly negatively associated with self-control, spiritual well-being, and hope (<i>P</i> &lt; 0.01). Self-control negatively affected depressive symptoms (<i>P</i> &lt; 0.01). BC patients` depressive symptoms were affected by self-control through 3 different pathways: the mediating role of spiritual well-being (95% CI: -0.062, -0.003), the mediating role of hope (95% CI: -0.119, -0.039); and the chain mediating roles of both spiritual well-being and hope (95% CI: -0.030, -0.001).</p> Conclusions <p>In this study, the prevalence of depressive symptoms was 79.3% among Chinese BC patients. Spiritual well-being and hope played chain mediating roles in the relationship between self-control and depressive symptoms among BC patients. In addition to improving self-control, the development of spiritual well-being and hope should also be included in BC patients' mental health treatment strategies.</p>