Aim: To synthesize Registered Nurses' self-reported perceptions and experiences of psychological well-being and ill-being during their first year of practice. Design: Qualitative meta-synthesis. Data sources: Databases included Cumulative Index of Nursing and Allied Health Literature, Excerpta Medica database, Medical Literature Analysis and Retrieval System Online and Psychological Information. Qualitative studies were considered for inclusion if published in English, from 2009-2019, reporting primary data analysis including psychological well-being and ill-being experiences of graduate nurses in first year of practice. Review methods: Qualitative studies were systematically identified and critically appraised. A meta-synthesis was applied using an open card sort technique to organize empirical data into a matrix of graduate nurses' voices of psychological well-being and ill-being. Results: Twenty-two studies were included. Analysis revealed patterns of positive experiences and emotions. These included feeling valued and part of the team and learning from and feeling supported by other nurses. Negative experiences and emotions such as feeling overwhelmed, stressed, alone and inadequately prepared were also identified. Conclusion: Graduate nurses' perceptions and experiences of their psychological well-being and ill-being revealed both positive and negative dimensions during this transition period. Specific examples of strategies that may promote transition nurses' well-being and prevent ill-being were identified such as social connection and support. Impact: Increasing the numbers of new nursing graduates world-wide is required to strengthen health systems. Developing strategies to retain these graduates in the workforce is paramount. This review found some graduate nurses experience the transition period as a time of personal growth and fulfilment, for others this period was a stressor. These findings were illustrated in a model of 'ways to well-being'. The potential for knowledge translation of this model extends from graduate nurses as individuals, to nurse entry to practice programs and graduate nurse programs, to organizational policy targeting future health workforce. Systematic review registration number: CRD42020148812.