While research has focused on understanding teachers' attitudes towards the inclusion of children with special educational needs into general education classrooms, there are lacunae that have yet to be addressed. This study examined the association between perceived self-efficacy and attitudes towards inclusion among elementary school teachers. The study also examined the role of teachers' self-efficacy as a mediating variable between knowledge of inclusion policy, perception of school support and teachers' attitudes towards inclusion. Teachers (N = 352) working in general or special education schools completed questionnaires assessing attitudes towards inclusion, sense of self-efficacy, knowledge of current policy, and perception of support for inclusive practices. Higher perceived knowledge of inclusion policy and higher perceived school support of inclusion were both related to higher self-efficacy regarding inclusion, which, in turn, was related to more positive attitudes about inclusion. Our results suggest that point to being knowledgeable regarding local and national policy is important in order to increase feelings of self-efficacy regarding the implementation of effective educational practice. To enhance inclusion, local and national policy must be clearly communicated to teachers. Furthermore, leadership and a supportive school environment are conducive to successful inclusive education.