Background/objectives: Emotional intelligence (EI) plays an important role in nursing education by supporting competencies such as communication, leadership, resilience, and clinical performance. In contemporary nursing education, students face increasing academic, clinical, and emotional demands, highlighting the need to identify modifiable factors that may be associated with EI and can inform student support strategies. Despite extensive EI research, evidence remains limited and inconsistent regarding how specific health-promoting lifestyle domains and sleep quality relate to EI among prelicensure nursing students. This study aimed to examine factors associated with EI and its relationship with health behaviors among prelicensure nursing students. Methods: A cross-sectional quantitative design was used. A convenience sample of 287 prelicensure nursing students from a local nursing school completed self-report questionnaires: the Schutte Self-report Emotional Intelligence Scale (SSEIS), the Health-Promoting Lifestyle Profile II (HPLP-II), and the Pittsburgh Sleep Quality Index (PSQI). Results: In structured multiphase regression, HPLP-II interpersonal relations (B = 4.42, 95% CI = 1.44 to 7.50, p = 0.004) and spiritual growth (B = 6.59, 95% CI = 3.81 to 9.37, p < 0.001) were positively associated with EI. Poor sleep quality (PSQI > 5) was negatively associated with EI (B = −1.95, 95% CI = −3.88 to −0.01, p = 0.049). Conclusion: Interpersonal relations, spiritual growth, and sleep quality were associated with EI among prelicensure nursing students. These factors may be relevant to consider when designing student support and EI-related educational initiatives; however, longitudinal and intervention studies are needed to clarify directionality and causality.