Seo Tai Ji is the debut studio album by Korean musician Seo Taiji, released in 1998. Although it is the first solo album by Seo, some refer to it as his fifth following the four albums released by Seo Taiji and Boys. The musician created the album entirely by himself, including playing every instrument and producing it. The album was released in 1998 while Seo lived in the United States and, with no promotion, it sold over 1.3 million units, making it one of the best-selling albums in South Korea.