The article analyzes the life and scientific achievements of Mykola Bilyashivskyi, a scientist-archaeologist, museologist, art historian, ethnographer, and analyzes the contribution of the scientist to the formation of museum studies in Ukraine. The author traces the formation of M. Bilyashivsky as a scientist and museologist, and highlights the historical conditions in which the academician lived and worked. Based on the analysis of scientific materials devoted to M. Bilyashivsky, it was found that he was born into a priestly family in the town of Uman in Cherkasy region, and studied at the Kyiv University of St. Volodymyr at the Faculty of Law. While studying, he became interested in history and attended lectures by the famous historian V. Antonovych. At this time, he became interested in archeology and took part in the first excavations. The author summarizes M. Bilyashivsky's ethnographic research in Cherkasy region, in particular the collection of oral history material among the residents of Pekariv village about Taras Shevchenko. On February 19, 1902, Mykola Fedotovych was elected director of the Kyiv Art, Industry and Science Museum of Emperor Nicholas Alexandrovich. Until 1923, M. Bilyashivsky was the permanent director of the museum. After M. Bilyashivsky took over the museum, he united like-minded people, true enthusiasts of museum affairs, and developed a program of the museum's activities. After the outbreak of the First World War, M. Bilyashivsky was mobilized into the active army. But thanks to the petition of the Russian Academy of Sciences, his service was peculiar. The scientist was appointed as the Academy's commissioner and had to deal with the protection of cultural monuments in Galicia. The author examines the activities of the scientist in the 1920s. It is established that during the Ukrainian Revolution M. Bilyashivsky was a member of the Central Rada, Commissioner for the Protection of Antiquities and Art of the Ukrainian People's Republic, and from September 1917 he headed the Department of Art Industry of the General Secretariat. In April 1918, he was elected an honorary academician by the Council of Professors of the Academy of Arts, and in 1919 he became an academician of the Ukrainian Academy of Sciences.