Udinsk (; , Khakhirai ÃÂrtöö) is a rural locality (a selo) in Khorinsky District, Republic of Buryatia, Russia. The population was 719 as of 2010. There are 10 streets.
Udinsk is located 43 km west of Khorinsk (the district's administrative centre) by road. Tarbagatay is the nearest rural locality.