Subways operate in South Korea's 4 largest cities, with 2 more cities currently building their own systems:

• Seoul (9 lines + 1 planned)
• Busan (2 lines + 1 under construction)
• Daegu (1 line + 1 under construction)
• Incheon (1 line, integrated with the Seoul subway system)
• Gwangju (1 line)
• Daejeon (1 line under construction)

Subway service in Seoul is provided by three separate operators: the Korean National Railroad, which operates Line 1, parts of Lines 3 and 4, and the Bundang Line; and two subway companies (see Seoul Metropolitan Subway for details).

See also

• List of Korea-related topics
• Transportation in South Korea