This study clarifies the concept of nurses’ self-management competency by identifying its attributes, antecedents, and consequences, and proposes a conceptual basis applicable to nursing education and clinical practice. Using Walker and Avant’s eight-step concept analysis (2019), we reviewed studies published from 2010 to 2025 across PubMed, CINAHL, RISS, KISS, and DBpia with the keywords “self-management,” “self-care,” “competency,” and “nurse.” Sixty-eight records were screened; twenty-eight met inclusion criteria for analysis. Results: Five defining attributes were derived—(1) self-awareness, (2) self-regulation, (3) emotional control, (4) resilience, and (5) self-development. Antecedents comprised personal factors (e.g., intrinsic motivation, self-efficacy, health literacy) and organizational factors (e.g., leadership support, training, work environment, feedback culture). Consequences included reduced presenteeism and burnout, improved job satisfaction and organizational commitment, increased health-promoting behaviors, and a strengthened patient-safety culture. Self-management competency is a core capability for sustaining professional performance among nurses. Systematic programs at educational and organizational levels are needed to enhance this competency.