The presented dataset contains information about alien vascular plant species found in the Middle Volga Region (South-East of the European part of Russia). In total, this dataset includes 413 species belonging to 248 genera and 67 families. The study is based on data published during floristic studies from 1852 to 2019. At the same time, the study does not include alien vascular plant species that have now disappeared from the territory of the region. In total, the dataset contains 7782 occurrence records which were extracted from the Salix information and analytical system developed at the Institute of Ecology of the Volga River Basin of the Russian Academy of Sciences (Senator et al., 2018).