We propose that personal relative deprivation (PRD)—the belief that one is worse off than similar others—plays a key role in the link between social class and prosociality. Across multiple samples and measures (total N = 2,233), people higher in PRD were less inclined to help others. When considered in isolation, neither objective nor subjective socioeconomic status (SES) was meaningfully associated with prosociality. However, because people who believe themselves to be at the top of the socioeconomic hierarchy are typically low in PRD, these variables act as mutual suppressors—the predictive validity of both is enhanced when they are considered simultaneously, revealing that both higher subjective SES and higher PRD are associated with lower prosociality. These results cast new light on the complex connections between relative social status and people’s willingness to act for the benefit of others.