Ilsan Line is a subway line operated by Korail, in Seoul, South Korea. Trains from this line continue to and from Seoul Metro's Line 3.

The Korea Railroad Corporation (Korean: 한국철도공사; Hanja: 韓國鐵道公社, branded as KORAIL, is the national railway operator in South Korea. Currently, KORAIL is a public corporation, managed by Ministry of Land, Infrastructure and Transportation.