Posttraumatic stress disorder (PTSD) remains a highly stigmatized disorder despite its prevalence. Given that the origin of stigmatization is rooted in cognitive representations that people hold, stigma may be differentially exhibited by people with varying degrees of cognitive flexibility. Intellectual humility, the recognition of one’s own intellectual shortcomings or flaws, may allow for flexibility in how people navigate knowledge surrounding PTSD, which may reduce stigma and improve interpersonal interactions with individuals with PTSD. The present study investigated whether intellectual humility would negatively predict PTSD stigma and social distance, above and beyond demographic factors and personal or social experience with individuals with PTSD. Participants ( N = 421, 67.2% men, mean age = 37.45, SDage = 9.99) completed a multidimensional measure for intellectual humility and the Mental Illness Stigma Scale adapted to assess PTSD stigma. Results confirmed our preregistered predictions. Bivariate correlations demonstrated that overall intellectual humility was negatively correlated with overall PTSD stigma, and overall intellectual humility was negatively correlated with overall social distance. That is, intellectually humble people reported less PTSD stigma and desired closer social distance with individuals with PTSD. Additionally, hierarchical multiple regression revealed that intellectual humility predicted unique variance in PTSD stigma and social distance above and beyond the contribution of demographic factors and personal experience or social relationships with someone with PTSD. These results may provide a useful framework for approaching and minimizing stigma toward PTSD.