Bomnak (Russian: Бомнак) is a rural locality (a selo) in Zeysky District of Amur Oblast, Russia, located on the northern bank of Zeya Reservoir.

A local road leads west to Gorny and Verkhnezeysk.

Bomnak has a dry-winter subarctic climate (Köppen climate classification Dwc) with dry, bitterly cold winters and warm, wet summers.