Background: High levels of mental well-being might protect against the onset of mental disorders but longitudinal evidence is scarce. This study examines whether flourishing mental health predicts first-incidence and recurrent mental disorders 3 years later. Methods: Data were used from 4482 representative adults participating in the second (2010–12) and third wave (2013–15) of the Netherlands Mental Health Survey and Incidence Study-2 (NEMESIS-2). Mental well-being was assessed with the Mental Health Continuum-Short Form (MHC-SF) at the second wave. The classification criteria of this instrument were used to classify participants as having flourishing mental health: high levels of both hedonic well-being (life-satisfaction, happiness) and eudaimonic well-being (social contribution, purpose in life, personal growth). DSM-IV mood, anxiety and substance use disorders were measured with the Composite International Diagnostic Interview (CIDI) 3.0 at all waves. Odds ratios of (first and recurrent) incident disorders were estimated, using logistic regression analyses adjusting for potential confounders. Results: Flourishing reduced the risk of incident mood disorders by 28% and of anxiety disorders by 53%, but did not significantly predicted substance use disorders. A similar pattern of associations was found for either high hedonic or high eudaimonic well-being. Significant results were found for substance use disorders when life-events and social support were removed as covariates. Conclusion: This study underscores the rationale of promoting mental well-being as a public mental health strategy to prevent mental illness. In wealthy European nations it seems fruitful to measure and pursuit a flourishing life rather than merely high levels of hedonic well-being.