From Incheon international airport

taxi

TAXI

Travelling by taxi from ICN offers a great flexibility getting to Seoul. There are a few distinct fully licensed services
Standard Taxi, Deluxe Taxi and Jumbo Taxi for up to 9 passengers. The fare range will vary from \50,000.
As the estimated fare is based on no traffic congestion, the actual rate may vary and it is advised to allow extra time for rush hour delays. Please note that you will be expected to be charged for Toll charges for highway use of \7,700.
The estimated travelling time to Seoul City Hall on a non-rush hour time will be around 60 minutes.

airline

AIRLINE BUSES

From Incheon Internation Airport, you will reach in the major hotels approximately 60-120 minutes and it will allow extra time for rush hour delays. You may get information on limousine and buses and purchase the bus ticket at the Transportation Information Counter (near the exit No. 2, 4, 9, 13) on the arrival floor (1st floor) of passenger terminal. You will get more information through this web page.
For more information on the bus service and guidance please visit the Incheon Airport website
http://www.airport.kr/pa/en/a/3/1/1/index.jsp

Express Train

Express Train

Please visit http://www.airport.kr/pa/en/a/3/1/2/index.jsp
You could find more information. There are other ways to arrive downtown Seoul. You could get more information at the information center of the airport

From Kimpo international airport

taxi

TAXI

There are two types of taxis at the airport, regular, and deluxe taxis. If you are traveling light and are alone or with one companion, the regular taxis will be fine. The deluxe taxis provide better service (sometimes an English speaking driver), are larger, and provide more luggage space. The fare for the deluxe is almost twice that of the regular. Regular taxi fare for the major hotels is about 25,000 won ($20). Deluxe taxi fare is about 47,000 won ($38). Travel time to the major hotels will be from 30 to 90 minutes, depending on the location and the traffic.
https://www.airport.co.kr/gimpoeng/content/contents.do?cid=2016010811264189412&menuId=1837

airline bus

AIRLINE BUSES

The best way from the airport is the Korean Airlines (KAL) Bus. KAL buses leave frequently from all terminals and go to all the major hotels in Seoul. There is a sign at the bus stop showing the routes and stops for specific hotels. Tickets are sold at the KAL bus counter inside the terminal. The fare is a very reasonable 6,200 won ($5). Travel time is almost the same as a taxi, 30 to 90 minutes, depending on your stop and the traffic. You will get more information from the web page.
http://www.kallimousine.com https://www.airport.co.kr/gimpoeng/extra/bus/busList/layOut.do?busType=I&cId=2016010811255234804&menuId=1834

SUBWAY SUBWAY

SUBWAY

The subway line No.5 (Purple) and No. 9 (Gold) are available from the Kimpo airport. You can get to your destination including major hotels, famous places in Seoul, Please visit the following website for more information on the Seoul subway system. Please visit the following website for more information on the Seoul subway system.
https://www.airport.co.kr/gimpoeng/content/contents.do?cid=2016010811261164820&menuId=1835

https://www.seoulmetro.co.kr/station/download.html