Experiences with weight stigma negatively impact both psychological outcomes (e.g., body dissatisfaction, depression) and behavioral outcomes (e.g., dieting, exercise). However, not everyone is equally affected by experiences with weight stigma. This study examined whether internalized societal attitudes about weight moderated the impact of weight stigma. Adult participants (n = 111) completed measures of experiences with weight stigma, as well as two indexes of internalized societal attitudes (the moderators): Internalized anti-fat attitudes and internalization of societal standards of attractiveness. Psychological outcomes included self-esteem, body dissatisfaction, drive for thinness, and bulimic symptoms; behavioral outcomes included avoidance of exercise and self-reported exercise behavior. Weight stigma was positively correlated with body dissatisfaction, drive for thinness, and bulimic symptoms, and was negatively correlated with state and trait self-esteem. Both indexes of internalized attitudes moderated the association between weight stigma and avoidance of exercise: Individuals high in anti-fat attitudes and high in internalization of societal standards of attractiveness were more motivated to avoid exercise if they also experienced a high degree of weight stigma; individuals low in anti-fat attitudes and low in internalization were relatively unaffected. Avoidance of exercise was negatively correlated with self-reported strenuous exercise. These findings suggest that weight stigma can negatively influence motivation to exercise, particularly among individuals who have internalized societal attitudes about weight. Reducing internalization might be a means of minimizing the negative impact of weight stigma and of facilitating healthy weight management efforts.