The study adopted explanatory research design, cross-sectional survey as research strategy, qualitative research approach, the population were 10 writers, the data was acquired through primary source, the procedure of acquiring data was to examine what other writers had written concerning the topic under study. The sampling design were survey of research papers published by academic journals and papers published at various websites. The objectives of the study were achieved and the problem statement was Relevance of applying Universal Education Theory and other educational theories in the 21st century. The introduction was brief of history of education. The study found out significance of education, the various kinds of educational theories, impact of educational theories, how to apply educational theories, causes of students' poor performance in academics, implication of behavioral, the formula of Universal Education (UE), cognitive theories ; problems teachers face in the classrooms. The study generalized that application of universal education theory and other educational theories were important in the 21st century. The study motivated teachers to study learning theories and used them for the benefits of their students. Keywords: Universal Education Theory, Educational Theories, Educational theories in the 21st century, applying educational theories,