This present study aimed to explore the relationship between upward social comparison, relative deprivation, belief in a just world, and delay discounting by surveying 614 college students. The results showed the following: (1) upward social comparison could significantly and negatively predict individuals' delay discounting; and (2) belief in a just world and relative deprivation had a chain mediating effect on the impact of upward social comparison on delay discounting. Specifically, when individuals experienced more upward social comparison, their belief in a just world will be weakened, which increased feelings of relative deprivation and ultimately led them to be more likely to choose the recent but smaller rewards and forego rewards that require waiting but are larger.