Weight stigma is increasingly prevalent, highly distressing, and associated with an array of negative health and psychological outcomes. Many of the known correlates - depression, stress, and weight gain - have the potential to be particularly harmful in the context of pregnancy and the postpartum, a life phase in which women's social roles, body weights, and body meanings are in particular flux. Yet, there is little literature connecting the experiences of weight stigma to the wellbeing of pregnant and postpartum women. 501 pregnant (n = 143) and postpartum (n = 358) women in the United States were surveyed between August and November of 2017. They answered questions about their experiences with weight stigma and standardized scale measures of depressive symptoms, perceived stress, maladaptive dieting behavior, emotional eating behavior, gestational weight gain, and postpartum weight retention. Regression analyses revealed that women experiencing weight stigma from more sources reported more depressive symptoms, maladaptive dieting behavior and perceived stress when controlling for pre-pregnancy BMI, parity, weeks of pregnancy or months since birth, and demographic covariates. Weight-stigmatizing experiences were also associated with more emotional eating behavior in pregnant participants and greater postpartum weight retention in postpartum participants. This preliminary study suggests that experiencing weight stigma may contribute to unfavorable physical and mental health outcomes for pregnant and postpartum women. These findings reflect the powerful negative social meanings of weight gain faced in pregnancy and often unachievable social standards of "dropping the baby weight" as new mothers.