As a transdiagnostic vulnerability factor, low distress tolerance predicts a wide variety of psychopathology. The current article extends past research, which has typically adopted an individual-differences approach, by articulating a social-cognitive theory of momentary distress tolerance. This new model intentionally separates actions taken to remain engaged with distress (i.e., tolerance) from avoidance/escape actions associated with intolerance, and highlights willingness to experience distress as central to tolerance. In addition, self-efficacy for tolerating distress is highlighted as a central predictor of the tolerance/intolerance process, influenced by distress intensity and momentary psychological resources (e.g., hunger, tiredness, degree of life stressors, social support). Finally, the model also explains how repeated experiences of distress tolerance and/or intolerance coalesce into a global self-perception indicative of individual differences in distress tolerance. Reasons why the proposed model has the potential to overcome current challenges in distress tolerance research are reviewed, and future directions for both research and clinical practice are highlighted.