In 2013, the Research and Development Foundation of the College of Education (RDFCEI, March 2014) of the University of the Philippines conducted a study in 12 selected public schools in regions participating in the Philippines’ Response to Indigenous and Muslim Education (PRIME) Programme. The study assessed the readiness of PRIME public schools to provide and sustain Inclusive Education (IE) services for Indigenous Peoples (IP) and Muslim children with disabilities. Findings revealed that educators have divergent views regarding IE, and recommended that the harmonization of existing definitions of inclusion is essential before the implementation of IE. This article explains the methodology implemented to conceptualize IE (RDFCEI, June 2014). Seventy-five (75) key officials of Special Education, Muslim Education, IP Education, and Alternative Learning System, and of the Central Office of the Department of Education participated in eight (8) focus group discussions regarding their views and experiences regarding exclusion, inclusion and IE. The resulting definitions of IE by each group were critiqued and a working definition was formulated through consensus building during a plenary session. This working definition incorporates nine essential aspects, reflects internationally established principles of inclusion and promotes Education for All. It places diverse Filipino learners at the heart of education that underscores acceptance, equal opportunities and non-discriminatory practices; and acknowledges and cultivates cultural diversity and multiculturalism. However, it is unique in recognizing and respecting one’s kapwa (the unity of the one-of-us-and-the-other) (Enriquez, 1976, 1995) and spiritual beliefs, as well as including adult learners through learner-centered andragogy.