© 2020, Springer Nature B.V. Our research examines the relationship between just-world beliefs and helping. Specifically, we pose that the belief in just world increases helping intentions via perceptions of meaning in life. Consistently, across two studies we found that higher levels of just-world beliefs corresponded with stronger helping intentions. In Study 1, individual differences in just-world beliefs correlated positively with helping intentions. In Study 2, experimentally induced higher (vs. lower) levels of just-world beliefs led to stronger intentions to help others. In both studies, we found that the presence of meaning in life mediated the effects of just-world beliefs on helping intentions, indicating that these prosocial effects of just-world beliefs are established through the impression that life is meaningful. We further found that positive affect plays a mediational role in these effects by linking the perceptions of meaning to helping intentions. This research provides insights into the socially desirable consequences of just-world beliefs by highlighting the crucial roles of existential appraisals and affective states.