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

It is located in the center of the oblast.

The area of the district is 1,349 square kilometers (521 sq mi).

[2] Its administrative center is the town of Sengiley.

[8] The population of Sengiley accounts for 29.9% of the district's total population.