The thesis explored the role of metacognition, worry and rumination in stress and recovery and is grounded in the Self-Regulatory Executive (S-REF: Wells and Matthews, 1994) model. The concept of recovery is difficult to define and therefore, three definitions of recovery were used to ensure this concept was evaluated across a variety of contexts. A multi-method approach was used that incorporated both experimental and quasi-experimental designs, which included a review of the existing literature, experimental manipulations, cross-sectional and longitudinal designs. Data included psychological and physiological outcome measures that were evaluated in analogue and clinical samples. Chapters 1 and 2 provide an overview of the thesis and the methodologies used throughout. Chapter 3 (study 1) includes a systematic review of the literature on the role of metacognition in bouncing back from stress, which provides a backdrop for the thesis. The results highlighted that two aspects of metacognition (metacognitive beliefs and coping strategies) were found to be related to factors indicative of resilience. In particular, metacognitive beliefs were positively associated with increased stress levels, and worry and punishment were associated with increased stress symptoms. Chapters 4 and 5 were experimental manipulations of strategies central to the metacognitive model (worry and rumination) and metacognitive beliefs (e.g., thought importance), and evaluated their effects on recovery from stress. Thinking styles and metacognitive beliefs delayed recovery from psychological stress with some evidence of different impacts on psychological and physiological indices. Subsequent to this Chapter 6 focused on further validation of the Detached Mindfulness Questionnaire and confirmed the five factor solution of the scale. Chapter 7 evaluated the metacognitive predictors of resilience, psychological distress (anxiety and depression), and clinically defined recovery from stress. Negative metacognitive beliefs and detachment were found to predict resilience such that increased resilience was associated with increased detachment and decreased negative metacognitive beliefs. In addition, negative metacognitive beliefs positively predicted psychological distress two months after initial assessment, while greater detachment positively predicted recovery from psychological distress. Finally chapters 8 and 9 evaluated the role of metacognition in recovery from stress in clinical populations (individuals receiving group metacognitive therapy). Predictors of change in metacognitive therapy were evaluated using SEM, which demonstrated that changes in metacognitive beliefs precede changes in symptoms of distress. Finally, a feasibility study was conducted of two psychological therapies (MCT and MBSR) in treating a transdiagnostic sample. Both treatments were found to be acceptable and feasible, and preliminary evidence indicated that metacognitive therapy may be the more effective intervention. The results produced two broad themes. The first is that metacognitive beliefs and thinking styles impacted on recovery from stress, which was found across populations, settings, and definitions of recovery. The second is that the detachment component of detached mindfulness predicted recovery from stress, such that greater detachment was associated with an increased probability of recovering. Further research is needed to explore the effect of metacognition on additional aspects of recovery. In summary, the thesis supports the idea that metacognition and thinking styles as implicated in the S-REF model play an important role in recovery.