The role of values-based action in facilitating change is central to Acceptance and Commitment Therapy but more peripheral in more traditional mindfulness-based interventions. This paper examined the role of values-based action in the relationship between mindfulness and both eudemonic and hedonic well-being in two samples—an undergraduate sample (n = 630) and a postgraduate sample (n = 199). It was hypothesized that mindfulness would be related to well-being indirectly through values-based action, measured as decreases in psychological barriers to values-based action and increases in values-congruent behavior. In both samples, significant indirect effects were identified from mindfulness to hedonic and eudemonic well-being through values-based action. These studies provide initial evidence that mindfulness effects well-being partly through facilitating meaningful behavioral change. The implication of this finding is that mindfulness interventions may be enhanced with an explicit focus on values clarification and the application of mindfulness to values-based behavior.