Discounting rate refers to people’s tendency to reduce the rate of subjective value from delayed benefit over time. The current study investigates the relationship among belief in a just world (BJW), sense of control, and discounting rate, especially the mediating effect of sense of control between BJW and discounting rate. The study recruited 412 undergraduates to complete a BJW scale, Sense of Control scale, and the Monetary Choice Questionnaire. The results show that (1) BJW positively predicted sense of control, (2) BJW and sense of control were negatively correlated with discounting rate, and (3) sense of control completely mediated the associations between BJW and discounting rate. These findings extend those of prior studies and indicate that a sense of control underlies the association between BJW and discounting rate.