The Irish education system, specifically about DEIS and mainstream schools, has only been superficially researched by academics (Conlon, 2014). While incorporating levels of Teacher Job Satisfaction and Teacher Self-Efficacy, this study utilizes a factorial, two two-way between-groups design among (N=215) secondary teachers within Irish institutions. The study generated mixed results, supporting previous research with a positive relationship between the levels of teacher self-efficacy and teaching job satisfaction, failing to support a monotonic relationship, as was previously researched. These findings were exploited and discussed, concerning their potential future applications as well as theoretical and practical implications. For instance, Locke’s (1976) range of affect theory and Herzberg’s motivator-hygiene theory may support the results computed in this study. The strengths and limitations of the study were also addressed, noting a limitation in the gender discrepancy in the sample but still may corroborate with previous literature and statistics who have reported large samples of female teachers (Reilly, Dhingra & Boduszek, 2014). Finally, a strength of this study would be the large sample size of schools contacted, successfully contacting many of all secondary schools within the Republic of Ireland, which may give rise to attention from researchers and policymakers.