Biysk is a city located in the Altai Krai region of Russia. It is situated on the Biya River, positioned near the point where it joins with the Katun River.
As the second largest city in Altai Krai, Biysk has seen its population fluctuate over recent decades. According to census data, the population was 233,238 in 1989, decreasing to 218,562 in 2002, 210,115 in 2010, and reaching 183,852 by 2021.