Kosan may be: Kosan County, a county in Kangwon Province, North Korea Kosan Biosciences, American pharmaceuticals company Ube Kosan Open, golf tournament played at the Ube 72 Country Club, Yamaguchi, Japan Kosan, art name of Joseon politician Yun Sŏndo
People with the surname Kosan include: Anja Kosan (born 2002), German rhythmic gymnast (born 1948), German Politician
See also
Ko San, South Korean cosmonaut