Background: Several studies have been undertaken regarding civilian and military nurses’ training, deployment, and experiences during missions in war and conflict areas. However, no review study regarding the experiences of nurses in serving in war and conflict areas has been published. Aim: This review aims to identify the views, experiences, and support needs of Registered Nurses when caring for patients in war and conflict areas. Method: Four electronic databases—MEDLINE, CINAHL, PsycINFO, and general BC PubMed—were searched in this systematic review. Study screening and selection, data extraction, quality appraisal, and narrative synthesis were conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 checklist. Results: Twenty-five studies were included in the final review. The findings were categorised based on four main themes: Challenges in nursing practice, Meaning of experience, Scope of practice, and Nursing support pre- and post-conflict. Conclusions: Registered Nurses play a critical role in prehospital care and have a significant impact on the survival of wounded military personnel and civilians and on their mortality. Registered Nurses play important roles in military deployment, with barriers to their successful implementation experienced due to a lack of information at the decision-making level, and the need for psychological supports and role-appropriate medical readiness training. Implications: Registered Nurses who are military-ready need to be effective in war and conflict areas. Using the experiences of military or civilian Registered Nurses to assess the pre-deployment preparation needs of these nurses will be beneficial to the effectiveness of the nursing workforce. There are elements that demand more attention during the pre-deployment preparation phase of nurses required to serve in war and conflict areas.