This bibliometric research aims to analyse inclusive education research from 1999 to 2018 as illustrative of worldwide trends regarding inclusive education. Five core issues consistently emerge from this analysis, and they are listed in chronological order as follows: Para-educational experiences and peer supports, pre-service and in-service teachers' attitudes, outcomes, and achievements of students with disabilities, teacher education/training, and teachers' efficacy. Their relationship was interdependent and supplementary to one another. From the results, several potential themes have emerged, such as inclusive education in multicultural environments, inclusion in higher education, relevant debates, and policies on inclusive education. From the evolutionary trajectory of inclusive education research, universal education may become a major future trend of research into Sustainable Development Goals (SDGs).