Purpose: Nursing is a job that is rewarding but also subject to a lot of work-related stress. It is necessary to understand the happiness of nurses in their personal and professional lives and to devise ways to increase their happiness. Methods: Based on extensive literature review and many years of experience, Comprehensive Nurses’ Happiness Model was developed by selecting concepts and linking antecedent factors, mediators, and outcome variables. Result: Personal and professional factors were presented as antecedent factors affecting nurses’ happiness. Personal antecedent factors included health status, economic status, leisure time, optimism/extroversion, and spirituality. The occupational factors include nursing readiness, work characteristics, and work environment as sub-factors, and the work characteristics sub-factors include nursing professionalism, job satisfaction, and turnover intention, and the work environment sub-factors include staffing, leadership, collaboration with physcians, and collaboration with nursing colleagues. In the process of moving from personal and occupational antecedents to the outcome variable of happiness, happiability as positive self-regulation competency and good relationships were presented as mediating factors. the outcome variable, nurses’ happiness, includes pleasure and meaning of life, and further includes the concept of expanding happiness to others and future generations. Conclusion: It is necessary to train nurses’ happiability and develop good relationships with strong and weak ties to increase happiness of nurses.