BackgroundLabour companionship refers to support provided to a woman during labour and childbirth, and may be provided by a partner, family member, friend, doula or healthcare professional. A Cochrane systematic review of interventions by Bohren and colleagues, concluded that having a labour companion improves outcomes for women and babies. The presence of a labour companion is therefore regarded as an important aspect of improving quality of care during labour and childbirth; however implementation of the intervention is not universal. Implementation of labour companionship may be hampered by limited understanding of factors affecting successful implementation across contexts.ObjectivesThe objectives of the review were to describe and explore the perceptions and experiences of women, partners, community members, healthcare providers and administrators, and other key stakeholders regarding labour companionship; to identify factors affecting successful implementation and sustainability of labour companionship; and to explore how the findings of this review can enhance understanding of the related Cochrane systematic review of interventions.Search methodsWe searched MEDLINE, CINAHL, and POPLINE K4Health databases for eligible studies from inception to 9 September 2018. There were no language, date or geographic restrictions.Selection criteriaWe included studies that used qualitative methods for data collection and analysis; focused on women’s, partners’, family members’, doulas', providers', or other relevant stakeholders' perceptions and experiences of labour companionship; and were from any type of health facility in any setting globally.Data collection and analysisWe used a thematic analysis approach for data extraction and synthesis, and assessed the confidence in the findings using the GRADE‐CERQual approach. We used two approaches to integrate qualitative findings with the intervention review findings. We used a logic model to theorise links between elements of the intervention and health and well‐being outcomes. We also used a matrix model to compare features of labour companionship identified as important in the qualitative evidence synthesis with the interventions included in the intervention review.Main resultsWe found 51 studies (52 papers), mostly from high‐income countries and mostly describing women's perspectives. We assessed our level of confidence in each finding using the GRADE‐CERQual approach. We had high or moderate confidence in many of our findings. Where we only had low or very low confidence in a finding, we have indicated this.Labour companions supported women in four different ways. Companions gave informational support by providing information about childbirth, bridging communication gaps between health workers and women, and facilitating non‐pharmacological pain relief. Companions were advocates, which means they spoke up in support of the woman. Companions provided practical support, including encouraging women to move around, providing massage, and holding her hand. Finally, companions...