Visual working memory is thought to have a fixed capacity limit. However, recent evidence suggests that capacity is greater for real-world objects compared to simple features (i.e., colors). Here, we examined whether greater working memory for objects was due to greater memorability. In online samples of young adults, real-world objects were better remembered than colors, which was attributed to a higher proportion of high-confidence responses (Exp 1). Memory performance for objects was also improved compared to their scrambled counterparts (Exp 2), indicating that this benefit is unrelated to visual complexity. Critically, the specific objects that were likely to be remembered with high confidence were highly correlated across experiments, consistent with the idea that some objects are more memorable than others. Object memorability also predicted memory performance between objects within a display (Exp 3). These findings suggest that the object benefit in working memory may be supported by stimulus memorability.