Abstract The lion's share of research on secrecy focuses on how deciding to keep or share a secret impacts a secret-keeper's well-being. However, secrets always involve more than one person: the secret-keeper and those from whom the secret is kept or shared with. Although secrets are inherently social, their consequences for people's reputations and social relationships have been relatively ignored. Secrets serve a variety of social functions, including (1) changing or maintaining one's reputation, (2) conveying social utility, and (3) establishing friendship. For example, if Beth has a secret about a past misdemeanor, she might not tell any of her friends in order to maintain her reputation as an outstanding citizen. If Beth does share this secret with her friend Amy, Amy could interpret this as a sign of trust and think that their friendship is special. However, Amy could also choose to share Beth's secret with the rest of the friend group to show that she is a useful member with access to valuable information about others. Attention to these social functions of secrets emerges from a young age, and secrets play a prominent role in human relationships throughout the lifespan. After providing an overview of what is currently known about the relational consequences of secrecy in childhood and adulthood, we discuss how social and developmental psychologists could work together to broaden our understanding of the sociality of secrets. Future steps include incorporating more dyadic and social network analyses into research on secrets and looking at similar questions across ages. This article is categorized under: Psychology > Reasoning and Decision Making