Maynsky District (Russian: Ма́йнский райо́н) is an administrative[1] and municipal[5] district (raion), one of the twenty-one in Ulyanovsk Oblast, Russia.

It is located in the central and northern parts of the oblast.

The area of the district is 2,306 square kilometers (890 sq mi).

[2] Its administrative center is the urban locality (a work settlement) of Mayna.

[8] The population of Mayna accounts for 27.5% of the district's total population.