The article highlights the activities of museum institutions of Ternopil Region based on the documents and materials of the State Archives of Ternopil Region. A brief description of the documents composition and a list of archival collections containing information on this issue are given. The current state of museum and archival affairs development allows numerous researchers, local lore researches and historians to find necessary information for writing scientific papers on various topics. Public interest in the historical past is growing every year, and museums, as specialized institutions, provide an opportunity to get acquainted with the artifacts of the past. Documents kept in state storage in the State Archives of Ternopil Region (hereinafter – the State Archives) allow us to better cover this issue. The emergence of this study is determined by the tasks of clarifying the content and composition of documents related to the activities of museum institutions in Ternopil and the region and stored in the State Archives. All of this together actualizes the research issues. The purpose of this study is to analyse the composition and content of the documents and materials of the State Archives related to the activities of museum institutions of Ternopil Region. The object of study is the activity of museum institutions of Ternopil Region since their foundation on the basis of documents of the national archival fond. The subject of the article is the documents of the State Archives concerning the work of museum institutions of Ternopil Region. A holistic study of the problem will allow to better highlight the activities of the museum institutions, and will give impetus to further research in this area. The work is the first to provide the most comprehensive analysis of the State Archives source base related to this issue, and this is the scientific novelty of the study. The scientific and practical value of the results and main ideas of study is that the analysed factual material, theoretical provisions and conclusions can be used in writing generalised works on the history of Ukraine, the history of museum affairs, in archival studies, historiographical and local history publications, in the preparation of relevant special courses, and in practical teaching. This study is an attempt to simplify the search for information for further researchers of Ternopil museums, local historians, and all those interested in the museum business of their native land.