Selenginsky District (Russian: Селенги́нский райо́н; Buryat: Сэлэнгын аймаг, Selengyn aimag) is an administrative[1] and municipal[4] district (raion), one of the twenty-one in the Republic of Buryatia, Russia.

The area of the district is 8,269 square kilometers (3,193 sq mi).

[2] Within the framework of administrative divisions, Selenginsky District is one of the twenty-one in the Republic of Buryatia.

[1] It is divided into one town (an administrative division with the administrative center in the town (an inhabited locality) of Gusinoozyorsk), six selsoviets, and seven somons, which comprise thirty-six rural localities.

[4] The Town of Gusinoozyorsk is incorporated an urban settlement, and the six selsoviets and seven somons are incorporated as twelve rural settlements within the municipal district.