We investigate for the first time in a 9-day diary study whether fulfilling one's values predicts well-being or whether well-being predicts value fulfillment over time. The empirical associations between the importance of human values to individuals and their well-being are typically weak and inconsistent. More recently, value fulfillment (i.e., acting in line with one's values) has shown to be more strongly correlated with well-being. The present research goes beyond past research by integrating work from clinical, personality, and social psychology to model associations between value fulfillment and positive and negative aspects of well-being over time. Across a nine-day diary study involving 1434 observations (N = 184), we found that people who were able to fulfill their self-direction values reported more positive well-being on the next day, and those who fulfilled their hedonism values reported less negative well-being on the next day. Conversely, people who reported more positive well-being were more able to fulfill their achievement, stimulation, and self-direction values on the next day, and those who reported more negative well-being were less able to fulfill their achievement values. Importantly, these effects were consistent across three countries/regions (EU/UK, India, Türkiye), the importance people attributed to values, period of the week, and their prestudy well-being. These results help to understand the fundamental interconnections between values and well-being while also having relevance to clinical practice.