People value solitude in varying degrees. Theories and studies suggest that perceived importance of solitude varies considerably due to two sources: the person and the function of solitude experiences (e.g., privacy, creativity). What are the unique contributions of these two sources? In the current research, participants evaluated the importance of a variety of solitude functions. Building on a pilot study (1,542 US college students, 6 solitude functions), we collected a quota-based US representative sample (501 US residents, 22 solitude functions). Variance component analysis reveals that both individual variation (22%) and differences between solitude functions (15%) contributed to the variability of perceived importance of solitude. Crucially, the interaction between individual and solitude function accounted for a substantial amount of variance (46%). We further explored the personality predictors of people’s perceived importance of solitude. Contrary to the literature’s focus on Extraversion as the only relevant Big Five dimension for solitude, all five dimensions were relevant predictors. The magnitude and direction of the associations depended on specific solitude functions. These results suggest that the key to understanding people’s perceived value of solitude is people’s idiosyncratic priorities. Scientific inquiries on solitude must consider the fit between a person’s characteristics and the specific functions a solitary experience affords.