Background: Woman-centred care provides a fundamental, philosophical approach for midwives working around the globe. Such care is integral to the role of the midwife and to determining standards of practice. Few empirical studies have explored the meaning of woman-centred care, how midwives perceive this concept and use it in practice, and how midwives are educated to provide woman-centred care. Aims: To explore whether woman-centred care can be observed and measured; to investigate the concept of woman-centred care in the context of international midwifery practice; and to develop an internationally informed definition of woman-centred care. Objectives: Develop an instrument to measure woman-centred care behaviours and determine whether these behaviours can be observed; review and synthesise the empirical literature on woman-centred care; gain consensus from international midwives on the concept of woman-centred care; and create an internationally informed definition of woman-centred care. Methods: A mixed methods, multiphase, explanatory, sequential design was conducted in four phases using a variety of methodologies to address the aims and objectives of the research. Phase 1: A qualitative methodology informed the design of a scale to measure woman-centred care behaviours in midwives, and quantitative methods were used to validate the scale. The scale was piloted in a nested study in a three-arm randomised controlled trial in a simulation setting with student midwives. Phase 2: A five-stage integrative review methodology, incorporating a structured quality appraisal, was employed to review and synthesise the empirical literature where woman-centred care was an intervention or an outcome. Phase 3: A three-round Delphi study with an international panel of expert midwives was used to gain consensus to inform an evidence-based definition of woman-centred care. Phase 4: An evolutionary, theoretical, and colloquial concept analysis to synthesise and integrate the data obtained in Phases 2 and 3 was used to develop an internationally informed, evidence-based definition of woman-centred care. Results: Phase 1: The Woman-Centred Care Scale (WCCS) was developed to observe and measure woman-centred care behaviours; the WCCS proved to be a valid measure (when compared to two gold standards tools) and somewhat reliable. When two expert clinical midwives used the WCCS to rate recorded video performances of a simulated clinical skill, the intra-rater reliability of the WCCS was 0.946 (95% CI 0.831, 0.908; p<0.001) and 0.849 (95% CI 0.568, 0.954; p<0.001), suggesting that the scale was a stable measure for individual raters over time. Internal consistency for Rater A was 0.908 and for Rater B, 0.910. Inter-rater reliability for the whole scale was moderate (0.470; 95% CI -0.055, 0.744; p<0.001), suggesting the lack of a clear shared understanding of woman-centred care behaviours and/or a degree of subjectivity in performance interpretation and measurement. Phase 2: Seventeen studies were selected for analysis from an initial 1205 papers identified in the literature review. Three main themes and 10 subthemes were identified. The theme ‘woman-centred care in clinical practice’ contained sub-themes of ‘choice and control’, ‘empowerment’, ‘protecting normal birth’, ‘relationships’, and ‘the individual midwife’. The theme ‘woman-centred care in maternity services’ had subthemes of ‘model of care’, ‘of care’, and ‘maternity care systems’. The theme ‘woman-centred care and education’ had ‘registered midwives’ and ‘midwifery students’ as subthemes. The review concluded that woman-centred care is fundamental to, and seen as the cornerstone of, midwifery practice, yet a shared understanding of what woman-centred care means is lacking. Phase 3: A panel of 59 expert international midwives representing 22 countries participated in the Delphi study. A total of 59 statements about woman-centred care were developed using qualitative data obtained from the expert midwives. Statements were categorised as defining characteristics of woman-centred care (n=17); role of the midwife in woman-centred care (n=19); woman-centred care and systems of care (n=18); and woman-centred care in education and research (n=5). A total of 37 (63%) statements relating to woman-centred care reached the a priori consensus level of 75%. Although continuity of care is important to midwifery practice, it was not reported as a core characteristic of woman-centred care, and respondents noted that woman-centred care could be provided by any healthcare professional in any healthcare setting. Phase 4: The antecedents, attributes, and consequences of woman-centred care were developed from the synthesised findings of the theoretical data (Phase 2) and colloquial data (Phase 3) of the research and resulted in an internationally informed evidence-based definition of woman-centred care. Conclusion: This research has made several important contributions to knowledge about woman-centred care. The first scale to observe and measure woman-centred care behaviours was developed and validated. Key variations in woman-centred care in the international empirical literature were identified in themes of clinical practice, maternity services, education, and research. International consensus on woman-centred care was achieved and this clarified some previously held characteristics of woman-centred care. Finally, the first internationally informed, evidence-based definition of woman-centred care was constructed. Establishing a clear and concise international definition of woman-centred care has implications for midwives, for maternity care, and for women globally. Such a definition substantiates a philosophy to inform the education of midwives and other clinicians, and to guide research, including ongoing scholarship in measuring woman-centred care in professional practice. It offers a statement which can be used to benchmark the care provided to women and to inform policy and reform the provision of maternity services. It directs support to women to assist them to navigate increasingly complex maternal care systems to improve the health outcomes for each childbearing woman and neonate.