Inclusivity has become the cornerstone of many government policies for the development of education in the two largest post-Soviet countries, namely Russia and Kazakhstan. In this study, we focus on teachers’ attitudes towards inclusive education, taking into consideration individual and institutional factors that may promote or hinder the implementation of appropriate policies. The study was conducted in 2020 in Russia and Kazakhstan, and is based on a survey of secondary school teachers (N = 3444). The use of latent class analysis allowed us to demonstrate how exactly satisfaction with professional activity, assessment of support from colleagues and school administration, ideas about responsibility for the success of educational inclusion of different actors, professional burnout (both general and related to diversity), attitudes towards inclusive education of children with disabilities, and readiness to implement inclusive practices in professional activities are connected in the perception of teachers. Thus, the research presented in the article contributes to understanding the mechanisms and prospects for the development of educational inclusion in the post-Soviet space, taking into account the needs of teachers as key actors of inclusion, the satisfaction of which creates a stable support for the cultivation of inclusive values and practices of overcoming inequality in education.