Introduction: Work ability is the relationship between a person’s personality, health, lifestyle, and employment-related factors. There are, however, few studies evaluating the variables linked to school teachers’ work ability. The purpose of this study was to assess school teachers’ work ability and the factors that affect it. Methods: A cross-sectional study of secondary school teachers was carried out. Sociodemographic characteristics, physical activity, body mass index, low back pain (LBP), psychological factors, work-related factors, health-related quality of life (HRQoL), and work ability were all collected through the questionnaire. The association between potential factors and job ability was investigated using ordinal logistic regression. Results were presented using odds ratios (OR) and 95 % confidence intervals (CI). Results: Of 1280, there were 1037 (81.0%) teachers who returned the questionnaire. The majority (71.9%) of the participants had moderate work ability, while 22.6% had good, and 5.5% had poor work ability. None of them were particularly had excellent work ability. The factors associated with increased work ability in the multivariable analysis were better HRQoL, namely physical (OR 1.11, 95%CI: 1.07, 1.15) and mental (OR 1.12, 95%CI: 1.06, 1.16) health and wellbeing. Conclusion: Positive associations exist between a teacher’s work ability and their physical and emotional well-being. Henceforth suggesting that these factors should be incorporated in workplace health promotion programs to maintain teachers’ work ability.