People with prolonged grief disorder (PGD) are at risk of public stigma, but research has yet to examine whether stigma is shaped by different types of relationship losses. In an experimental study, we asked participants (N = 306) to read three scenarios in which targets lost their romantic partner, child, or companion animal. Targets with PGD (vs. integrated grief) elicited more negative emotional reactions and attributions, and their experiences were perceived as less legitimate. Targets who lost their companion animal (vs. other relationship losses) were perceived as the most sensitive and their grief as the least legitimate, but they also elicited the lowest prosocial and fear reactions and were perceived as the warmest. Lastly, targets with PGD who lost their companion animal (vs. other relationship losses) elicited more negative emotional reactions and attributions, and their experiences were perceived as less legitimate. Implications and suggestions for future studies are discussed.