Korea Railroad Corporation, promoted as Korail, is the national railroad operator in South Korea. Korail operates metros, passenger and freight trains throughout South Korea. The railroad's headquarters are located in Daejeon.

Korail operates all the long distance lines in South Korea as well as local lines. The Gyeongbu Line with its high-speed parallel line, running between the two largest cities, Seoul and Busan, is by far the most heavily travelled line. Other main lines include Honam Line and Jeolla Line, stretching into Jeolla region, the Janghang Line and the Jungang Line.