Aim/Purpose: The year 2020 marks the 50th anniversary of the first official definition of the term “transdisciplinarity.” This paper focuses on a critical analysis of the development of modern transdisciplinarity since its inception. Background: The article presents two main directions for the development of transdisciplinarity. It also shows its identification features, strengths, and weaknesses, as well as the significant role transdisciplinarity plays in science and education. Methodology: The methodology employed in this article is a content analysis of resolutions of international forums as well as articles on transdisciplinarity published from 1970 to 2019. Contribution: For one reason or the other, several of these authors did not quote the opinions of the original authors of transdisciplinarity. The subsequent use of those articles by other authors thus posed some ambiguities about the place and role of transdisciplinarity in science and education. The advent of e-databases has made it possible to access the original forum articles. This further made it possible to refine the original content of the term “transdisciplinarity” and to trace its development without mixing it with vague opinions. Based on these findings, the perception of transdisciplinarity as a marginal trend in science and education could be eliminated. Findings: This paper shows how modern transdisciplinarity is developing into two main directions: transdisciplinarity in science as well as transdisciplinarity in education. These orientations have individual goals and objectives. The transdisciplinarity of scientific research helps to complete the transformation of the potential for interdisciplinary interaction and the integration of disciplines. Whereas, in education, transdisciplinarity (meta-discipline) is about developing an international standard for transdisciplinary education and also describing the content of transdisciplinary competence for students of diverse disciplines at all levels of higher education (bachelor’s, master’s and postgraduate studies). Recommendation for Researchers: Transdisciplinary research involves the interaction of people with disciplinary knowledge plus a degree of scientific outlook. Since disciplinary knowledge domains remain in their disciplinary boxes, it is, therefore, advisable to generalize disciplinary knowledge rather than force them to interact. This is the basis for proposing the systems transdisciplinary approach—which provides a methodology for unifying and generalizing disciplinary knowledge. Future Research: As the research shows, the organizers of modern international forums do not take into account the division of transdisciplinarity development trends. To increase the effectiveness and significance of such forums, it is necessary to return to the practice of organizing special international forums on the transdisciplinarity of science and that of education.