Objective: To describe the experiences of registered nurses (RNs) who support breastfeeding women and to understand the factors that they believe affect practices that support breastfeeding. Data Sources: We conducted an online search using five databases: Scopus, MEDLINE, Cumulative Index of Nursing and Allied Health Literature (CINAHL), the Cochrane Database of Systematic Reviews, and Joanna Briggs Institute of Systematic Reviews. Study Selection: We included original research articles on the experiences of RNs who support breastfeeding women that were published in 2009 or after and were available in English. After title and abstract review of 785 articles, we included 22 articles for full text review. Nine articles met the eligibility criteria and were included in the review. Data Extraction: We used Whittemore and Knafl's five-step framework and the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines to guide this integrative review. Three authors reviewed and appraised the articles independently. Data Synthesis: We categorized the findings into three themes: Workplace Issues, Personal Experiences, and Breastfeeding Knowledge and Education. Workplace Issues included the subthemes Lack of Time and Workload and Infant Health Stability. Personal Experiences included the subthemes Attitudes, Individual Experiences With Breastfeeding, and The Experiences of Family and Friends. Breastfeeding Knowledge and Education included the subthemes Prelicensure Education and Workplace Education and Training. Most researchers identified deficits in knowledge and education among RNs. The concept of confidence was influenced by all the other themes. Participants in the included studies reported that they developed confidence after learning from lactation consultants and having role models who supported the development of their knowledge and skills. Conclusion: Despite the heterogeneity among the studies, findings highlighted the need for an increased focus on the preparation of RNs to support women to effectively breastfeed within health care organizations. Multitargeted efforts, such as orientation programs and in-depth breastfeeding education using role modeling, mentorship, and role playing with practical scenarios, may improve RNs’ abilities and confidence to support breastfeeding women.