Incheon Subway Line 1 is a 30.3-kilometer (18.8 mi) north-south subway line, part of the Incheon Subway system. The line is also included as a part of the overall Seoul Metropolitan Subway network; Bupyeong Station has a free transfer with Seoul Subway Line 1, Gyeyang Station connects with the AREX Line which leads to Incheon International Airport and Seoul Station, Bupyeong-gu Office Station has a free transfer with Seoul Subway Line 7, and Woninjae Station has a free transfer with the Suin-Bundang Line.

The Seoul Metropolitan Subway is a metropolitan railway system consisting of 23 rapid transit, light metro, commuter rail and people mover lines located in northwest South Korea. The system serves most of the Seoul Metropolitan Area including the Incheon metropolis and satellite cities in Gyeonggi province. Some regional lines in the network stretch out beyond the Seoul Metropolitan Area to rural areas in northern Chungnam province and western Gangwon Province, that lie over 100 km (62 mi) away from the capital.