The aim of the study. To systematize factual data on the formation and development of the competition system components in professional tennis before the beginning of the "tennis open era". Material and methods. Facts from the history of the formation of systematicity in professional tennis competitions and the formation of key competitions in the period up to 1968 was the main material of the research. The results. The era of modern tennis begins in the second half of the 19th century. It was found that the game began to be commercialized already in 1894, and this process began with the sale of tennis training equipment and textbooks. The first competitions, which were open to everyone, including professional tennis players, were held in Great Britain (Wimbledon tournament, 1875), but they cannot be called professional, since in British society attention was focused on the development and popularization of amateur sports. Summarizing the facts made it possible to find out that tennis began to develop as a professional sport in the United States, where were favorable economic and geopolitical conditions for this. Here, in 1926, the promoter K. Pyle held exhibition tours exclusively for professional tennis players with whom he concluded contracts. It was found that in the late 20s – early 30s of the XX century, three professional tennis majors of those times were created – U.S. Professional Championship, Wembley Professional Championships and French Pro Championship. These competitions actually set the pace for the development of the direction. It is established that characteristic for that time was a constant change in the number of participants, the format of holding and the surface of the tournament courts. The key barrier (separation between amateur and professional tennis) was overcome in 1968. In addition, the experience gained in the past in organizing professional tennis tournaments gradually received a new level of adaptation in the “Open Era tennis”. However, the period until the 1980s remained difficult to determine a unified attitude of the leading tennis organizations in the world to the process of its further professionalization. Conclusions. Tennis as a type of professional sport began to form in the US at the end of the 19th century and immediately developed dynamically, at the same time separated from the amateur (until 1968). The main tournaments (majors) of that time were the U.S. Professional Championship, Wembley Professional Championships and French Pro Championship, However, others tournaments developed too and they were even a priority for many leading professional tennis players periodically. The competition system was not stable, competition formats often changed, but professional tennis gained popularity and increasingly became a source of income for the athletes themselves and entire organizations.