Self-presentation is a fundamental aspect of social life, with myriad critical outcomes dependent on others’ impressions. We identify and offer the first empirical investigation of a prevalent, yet understudied, self-presentation strategy: humblebragging. Across 9 studies, including a week-long diary study and a field experiment, we identify humblebragging—bragging masked by a complaint or humility—as a common, conceptually distinct, and ineffective form of self-presentation. We first document the ubiquity of humblebragging across several domains, from everyday life to social media. We then show that both forms of humblebragging—complaint-based or humility-based—are less effective than straightforward bragging, as they reduce liking, perceived competence, compliance with requests, and financial generosity. Despite being more common, complaint-based humblebrags are less effective than humility-based humblebrags, and are even less effective than simply complaining. We show that people choose to deploy humblebrags particularly when motivated to both elicit sympathy and impress others. Despite the belief that combining bragging with complaining or humility confers the benefits of each strategy, we find that humblebragging confers the benefits of neither, instead backfiring because it is seen as insincere.