Seoinn Design Group is founded in 1978 by Architect, Choi, Dong-kyu in Seoul, Korea. Seoinn Design Group has been actively working  numerous award winning projects in Seoul, Korea.

Since 2010, Alex Yoocheol, Managing Director joined this group and has led numerous projects.

Seoinn Design won the Architecture Master Prize in Bilbao, Spain in 2019 for the Saemoonan Church 

Most of the famous projects are Saemoonan Church, Manrihyun Holyness Church, Somang Church, Mosegol, The Sarang Church and StayB Hotel.