If you're visiting South Korea for the first time, learning how to use the Seoul Subway may seem intimidating. With dozens of lines, hundreds of stations, and millions of passengers every day, it's one of the busiest subway systems in the world. The good news is that it's also one of the easiest, cleanest, safest, and most efficient public transportation systems you'll ever use. As someone who grew up in South Korea and still visits regularly, I almost always use the subway when I'm in Seoul. It's affordable, reliable, and often faster than taking a taxi, especially during rush hour. In this complete 2026 guide, I'll show you exactly how to use the Seoul Subway like a local—from buying a T-money card to navigating transfers, reading station signs, and avoiding common tourist mistakes. Why Use the Seoul Subway? The Seoul Metropolitan Subway connects nearly every part of the city and even extends to nearby areas such as Incheon, Suwon, and Seongnam. Here are a...