Seoul Subway Line 7

Seoul Subway Line 7 of the Seoul Metropolitan Subway was built from 1990 to 1996 (Jangam-Konkuk Univ.) and was completed on August 1, 2000 (central section 17 km. Konkuk University to Sinpung); the western section between Sinpung and Onsu was put into service on February 29, 2000. This north-south line does not run through the city centre but links Gangnam directly to the northeastern districts of Seoul. In 2019, Line 7 had an annual ridership of 380 million or 1.04 million passengers per day. Although most trains run between Jangam and Seongnam, some trains short turn at Onsu station and some trains start at Dobongsan station.

All trains on Line 7 are monitored by 1,008 closed-circuit television cameras that were installed in June 2012.

The extension to Incheon Subway Line 1 was designed to relieve the traffic congestion in western Seoul and northern Incheon. Nine stations were added on October 27, 2012, for the 10.2 km extension, starting from Onsu Station of Line 7 and ending at Bupyeong-gu Office Station of Incheon Subway Line 1. A western extension will add eight stations towards Incheon and will provide an interchange with Incheon Subway Line 1 and the AREX, while a northern extension will add six stations and will provide an interchange with the U Line.

Expansion
Line 7 was extended west of Bupyeong-gu Office. Construction on the two-station, 3.94 km extension to Seongnam began in 2013 and was completed on May 22, 2021. The extension will allow for transfers to Incheon Subway Line 2.

A further seven-station extension to Cheongna International City station through Cheongna International City is currently planned and is not expected to open any earlier than 2027; the extension will allow for transfers to the airport railroad. Another further two-station extension through Incheon's metropolitan landfill to Geomdan Oryu station is also currently being planned.

Line 7 is also being extended north of Jangam to Yangju and Pocheon in two phases. The first phase, which started construction in late 2019 and is planned to open in 2025, will feature two stations, one of which will be Tapseok station, providing transfers to the Uijeongbu LRT. The second phase, which is still in planning, will feature four additional stations. The second phase may be operated as a shuttle service.

Seoul Metro

 * Seoul Metro 7000 series
 * 1st generation – since 1995 (Retired)
 * 2nd generation – since 2000
 * 3rd generation – since 2010
 * 4th generation – since 2022
 * 5th generation – since 2022