For the past decade, the United States spent hundreds of billions of dollars annually on public welfare programs, yet over 30% of eligible individuals do not access benefits distributed through these programs. We propose that a key barrier to program participation is miscalibrated perception of public stigma-individuals' pessimistic impressions of the stigma with which the general public regards welfare-eligible people. First, we examine how people's own attitudes toward a welfare-eligible individual compare to their estimates of parallel attitudes among their peers and among the general public. Study 1 specifically categorizes spontaneous reactions to learning someone is eligible for Supplemental Nutrition Assistance Program (SNAP) benefits: stigma, negativity about help-seeking, pity, envy, willingness to help, happiness, and admiration. Using these seven dimensions, Studies 1 and 2 demonstrate widespread pluralistic ignorance of welfare stigma: Participants believed that they held more positive, and less negative, attitudes toward SNAP-eligible individuals than did their peers or the American public. Studies 3A and 3B utilize established, incentive-compatible designs from the pluralistic ignorance literature to reveal that participants held less negative personal views about the SNAP-eligible population than they believed others did. Study 4 demonstrates the causal potential of perceived public stigma to reduce individuals' intentions to apply for SNAP and to refer the program to peers. Study 5 tests an intervention with a SNAP-eligible population to demonstrate that perceived public stigma can indeed be decreased, although the observed decreases were not sufficient to increase near-term SNAP application or referral tendencies. (PsycInfo Database Record (c) 2025 APA, all rights reserved).