The paper contains a complete annotated list of freshwater ichthyofauna of the Middle Ob River basin. The list is based on an analysis of publications and on the results of the authors’ research, and it includes 43 species in two classes, 9 orders, 12 families, and 30 genera. Ten of all listed species are introduced and only seven are naturalized. For each species, taxonomic comments are provided where necessary and conservation status, distribution within the Middle Ob River basin, abundance and commercial value are indicated. Latin and English names are given.