Unlike Yiddish (_fargin_) and Sanskrit (_muditā_), English has no single word to describe the practice of sharing someone else’s joy at their success. Sympathetic joy has also escaped attention in philosophy. We are familiar with schadenfreude, begrudging, envy, jealousy, and other terms describing either (a) pleasure at someone else’s misfortune or (b) displeasure at someone else’s good fortune. But what, exactly, is sympathetic joy? I argue that it is a short-term or long-term feeling of great delight at another’s good fortune, (...) requiring no more than minimal understanding of the relevant person and event. It is intensified relative to understanding, sharing, and positive disposal. It is importantly different from empathetic emotions and also from vicarious pride. It may be group-directed. Empirical research suggests it occurs fairly often, activates the brain in the same way as does sympathetic sadness, and may increase our well-being. It is primarily not a reactive attitude (an emotional reaction to good or bad will), but, rather, a sign of good will toward another. (shrink)