Aim/Objective: This study aimed to examine how a buddy-supported onboarding program affected early-career nurses in medical-surgical units, focusing on their integration, perceived support, sense of belonging, confidence, competence, and turnover intention. Background: Early-career nurses often face significant obstacles when they enter clinical practice, including stress, low self-esteem, and a lack of professional support. These difficulties can increase job dissatisfaction and turnover intention, particularly in demanding settings such as medical-surgical units. Many healthcare organizations have adopted buddy-supported onboarding programs to help new nurses integrate, develop professionally, and stay in their roles. Design: The study used a qualitative phenomenological design. Method: The researcher recruited seven registered nurses with fewer than three years of clinical experience in medical-surgical units at King Abdulaziz National Guard Hospital in Al Ahsa, Saudi Arabia, using purposive sampling. Data were gathered through semi-structured, in-person interviews and analyzed thematically using Braun and Clarke’s approach. Results: The analysis produced six themes: structured onboarding supports early adjustment; buddy support acts as an emotional and practical anchor; a sense of belonging develops gradually and depends on team dynamics; psychological safety strengthens learning and confidence; inconsistent support hinders confidence development; and interpersonal and family-related factors shape turnover intention. Conclusions: Buddy-supported onboarding programs can build early-career nurses’ confidence, strengthen their professional integration, and ease their early adjustment. To support nurses’ transition and improve workforce retention, healthcare organizations should reinforce structured onboarding frameworks and ensure consistent coaching.