Although learning and preparing for future behavior are well-established functions of regret, social functions have been largely ignored. We suggest a new model of the functions of regret, the Privately Experienced Versus Expressed Regret model, in which private experience and public expression differentially serve these functions. The current research examined this model using both naturalistic and experimental approaches. In Study 1, we coded tweets about regret posted on social media to examine whether this content emphasized social relationships versus learning and preparation. Study 2 experimentally examined the hypothesized social closeness function for expression of regrets. Study 3 further examined how privately experienced and publicly expressed regrets differ on the social closeness and learning and preparatory functions. Studies 4 and 5 confirmed the specific social closeness function rather than global social benefits. This research suggests that the social expression of regret differs from private experience in both form and function.