Vilyuysky District (; , ) is an administrative and municipal district (raion, or ulus), one of the thirty-four in the Sakha Republic, Russia. It is located in the western central part of the republic and borders with Zhigansky District in the northeast, Kobyaysky District in the east, Gorny District in the south, Verkhnevilyuysky District in the west, and with Olenyoksky District in the northwest. The area of the district is . Its administrative center is the town of Vilyuysk. Population: 25,696 (2002 Census); The population of Vilyuysk accounts for 40.6% of the district's total population.
Main rivers in the district include the Vilyuy and its tributaries the Tyung and Chybyda, as well as the Tympylykan and Lungkha tributaries of the Lena.
The district was established on January 9, 1930.
As of the 2021 Census, the ethnic composition was as follows:
The economy of the district is mostly based on agriculture.
<small>Divisional source:</small><br /> <br/> <small>*Administrative centers are shown in bold</small>