Zaigrayevsky District (; ) is an administrative and municipal district (raion), one of the twenty-one in the Republic of Buryatia, Russia. It is located in the center of the republic. The area of the district is . Its administrative center is the urban locality (an urban-type settlement) of Zaigrayevo. As of the 2010 Census, the total population of the district was 49,975, with the population of Zaigrayevo accounting for 11.2% of that number.