Organisations are frequently confronted with the issue of how to enhance employee mental health. Based on self-determination theory, a model is proposed that examines the relationships between job crafting, the satisfaction of the intrinsic needs for autonomy, competence, and relatedness at work, and employee well-being—defined here as both subjective well-being and psychological well-being. A sample of 253 working adults completed a battery of questionnaires including the Job Crafting Questionnaire, the Intrinsic Need Satisfaction Scale, and the Mental Health Continuum. Using structural equation modelling methods, it was determined that job crafting predicted intrinsic need satisfaction, which, in turn, predicted employee well-being. The results suggest that job crafting may be an important underpinning upon which to base an employee well-being intervention.