Historically, nostalgia has been viewed as a disease of the brain or the mind. However, in recent years, nostalgia has received a conceptual rehabilitation due to a revival of scholarly interest accompanied by the use of contemporary empirical methods. Drawing upon this recent work, we propose that nostalgia is an important resource for psychological health and well-being. We begin by detailing the characteristics of the nostalgic experience and then discuss a wide range of studies demonstrating that psychological threat triggers nostalgia, nostalgia enhances psychological health and well-being, and nostalgia promotes adaptive psychological functioning among individuals at risk for poor mental health. We also highlight the need for future research on nostalgia's relation to psychological health.