In recent decades, there has been a growing body of research showing the relationship between teaching work and several health problems, both physical and psychological. Some of these studies relate personal competencies and resources to teachers’ occupational health. Based on the construct of Effective Personality, proposed by Martin del Buey, Martín Palacio, and Di Giusto, the aim was to analyse the relationship between the dimensions of the construct and Teachers’ Occupational Health. A descriptive cross-sectional design was used. It was based on the application of the Teacher Health Questionnaire (CSD) and the Efficacy Personality Questionnaire-Adults (CPE-A). The sample consisted of 700 non-university teachers aged between 26 and 66 years, M = 47.65 SD = 8.68. Descriptive, correlational, linear regression, and structural equation analyses were carried out. The results confirmed the relationship between the Efficacy Personality construct and Teachers’ Occupational Health (r = 0.45 **). In addition, the regression analysis indicated the relevance of each factor of Efficacy Personality in the factors of Teachers’ Occupational Health. The variance of Self-efficacy is the most explained by the dimensions of Efficacy Personality (40.2%), with positive relationships. The structural equation analysis confirmed the influence between Efficacy Personality and the factors of Self-Efficacy and Satisfaction, explaining 55.0% of the variance. It is concluded, therefore, that Efficacy Personality has a protective function on Teacher Occupational Health; the higher the Efficacy Personality scores are, the better the results in health gain—Self-efficacy and satisfaction—and the lower the result in health loss—burnout, cognitive affections, musculoskeletal affections, and voice alterations. These results facilitate the design of prevention and intervention programmes for teachers’ occupational health, which strengthen and improve personal and socio-affective competencies.