List of Gaon Album Chart number ones of 2021

The Gaon Album Chart is a South Korean record chart that ranks the best-selling albums and EPs in South Korea. It is part of the Gaon Music Chart, which launched in February 2010. The data is compiled by the Ministry of Culture, Sports and Tourism and the Korea Music Content Industry Association based upon weekly/monthly physical album sales by six major South Korean distributors: Kakao M, SM Entertainment, Sony Music Korea, Warner Music Korea, Universal Music and Stone Music Entertainment.